I know some people here, and more than just you two, Kathy & Janna, are not Ross Greene fans. That's OK, it has to be, because we're all dealing with different sorts of problems each in our own way. I recommend it so much because it was not only such a miraculous change offered to us, but it also made me change my way of thinking, drastically. if nothing else, learning to think laterally and recognise the need for change and adaptability, is helpful. Where you go, what you take from it - very much needs to be personalised. It works well for us. I wish it worked as well for you, but I do accept that it doesn't. A pity, but it's not a matter for blame or major disagreement. I might like chocolate, you might prefer strawberry. To each his own...
BBK, I'm the last one to offer much in the way of advice here - ages ago, we made the decision to not hassle the kids about untidy rooms. It comes at a cost, but it also means no meltdowns.
The kids crud their rooms, but it also means I refuse to enter those rooms. So if they have washing that needs doing, it simply won't get done unless the clothes make their way into the hall or laundry. If her room is too untidy for you to change her bed, she has to learn fast how to do it entirely on her own. When she's looking for her favourite dress to wear and it's in a crumpled heap on the floor with a sticky patch from an ice cream wrapper, it's "Oh, that's a pity, if you had found it sooner and brought it to the laundry I might have been able to wash it for you."
I have a routine that works for me. All I suggest is set up your own total household routine that works for you. having her room tidy shouldn't be on the agenda, to begin with. The art materials - if they aren't kept in order, they go out completely. It's YOUR creative space, she is only to use it if she respects it. Any other mess in the house - not acceptable. Any wrappers she drops and leaves - do not buy that food again for anybody in the house. My mother banned chewing gum from the entire house because my brothers would stick their wads of gum on the bed frames, under the dining table or on their desks. So - no gum for anybody, not the adults in the family, nor the other kids. Food only permitted in the kitchen and dining area. The only exception is me because I need to spend so much time resting - but as I'm the one who takes responsibility to ensure not a speck is left in my room (and I succeed) than I'm permitted to do it.
No soft drink in the rooms - bottle of water only.
Clean washing - this is my job (or whichever adult kid is helping me). I wash on my house-cleaning days (I have paid help because I can't manage a lot of tasks). I will ensure the washing is hung up carefully, t-shirts on hangers or folded over the line and pegged at armpits. No ironing needed. Business shirts & flannel shirts are hung on hangers, collar folded neatly, creases smoothed out, top button done up to help set the collar. No ironing needed in 99% of shirts. Trousers - folded along crease lines (zip done up, top button left undone to ensure they fold neatly). Hung on a stronger hanger, or folded over the line. They take longer to dry but shouldn't need ironing.
I get the washing in, folding and sorting carefully as I go. When the kids were younger I had a separate plastic washing tub for each person (got the idea from my sister and her five kids - each kid's clothing was colour-coded and had a colour spot inside, plus the same colour tub to put it in when clean).
Now, I simply put each person's clean clothes away for them. The adult kids, especially those with messy rooms, put their clothes away themselves. difficult child 3 does it while I watch, but most of his clothes I can hang up in his wardrobe (I can get to that without risking my ankle). That way I know I did my part of the job.
difficult child 1 is terrible at bringing me his dirty washing. I would ask, each washday, "Where are your dirty clothes?"
"haven't got any."
"What about underwear? What state is it in? Has it totally rotted to pieces yet? Do let me know when you need me to buy you more, after the previous lot has composted onto your body."
Now he lives mostly at girlfriend's parents' place, he has appearances to keep up. He gets his washing done there, so he tells me. he DOEs appear wearing clean shirts a lot more, so maybe he's telling me the truth. girlfriend is keeping him organised now.
difficult child 3 broke the rule about eating in his room. At an earlier time, so did easy child 2/difficult child 2 - she had a container of Jelly Bellys in her room.
Ant plague. Not pretty. We even had ants in our room, although there were no food scraps, not even a wrapper. They were after water, in our room. Once we stoppered all water bottles our room was clear. But difficult child 3's room - the ants had made a nest in his chest of drawers, inside the drawer casing (hollow plastic). He had to spend the night on our bedroom floor while we dragged out the furniture, fumigated it and sent him in with the vacuum cleaner to

up all the ants and their eggs. He was made to drag out stuff ono the floor and scout around for any residual wrappers, soft-drink bottles etc. Talk about consequences - difficult child 3 was the only one responsible and the only one who could safely get into his room.
He's much more careful now.
But his room is a mess. And the mess is spilling out into other parts of the house. I try to reclaim but I'm just not well enough. I throw away stuff from round the edges and where possible, I wash any clothes I can reach from the doorway and if they no longer fit difficult child 3, I give them away (after I've mended anything mendable). Frankly, because he no longer goes to mainstream school he no longer needs as many clothes. And clothes are a huge part of the problem, they take up storage space and unless they're regularly dragged out and checked for fit and condition, they can soon become outgrown and be a waste of storage space,
Today we were getting dressed up for easy child 2/difficult child 2's 21st birthday party. difficult child 3 literally didn't have anything suitable to wear - he lives in t-shirts & jeans. A few months ago we bought new jeans for him, he's already almost outgrown them. As he was getting ready today, he brought in shirts (on hangers) from his wardrobe - only one out of five shirts fitted him. The others are now loose on my bed. I can immediately give them to his younger friend because I know they are clean and in good repair (all clothes on hangers in this house are clean and neat, because of my 'system').
A friend of mine down the road suffers from depression, among other things. Her house is a mess - different from ours, but still overwhelming. But her mess was not functional (ours is mostly functional although it could be a lot better). She lives in one large house which was once two flats, so it's like a double laundry. it was full of clothes waiting to be ironed; clothes waiting to be folded; baskets here, baskets there, clothes waiting to be washed; and all of them mixed in together, with heaps falling over heaps. Where do you start?
Her problems began and got worse, the day she brought the washing in and didn't have time to immediately deal with it (depression does that to you). Then next time, she had twice as much and it was too overwhelming. But laundry doesn't go away. Especially if you have girls, they end up acquiring more clothes because they seem short of them, even with an overloaded laundry.
Just an example of how easily it can happen.
I still pick up a lot more than I should, in the rest of the house. I really recognise the kids who open something and leave the bits lying around. difficult child 3 cooks his own lunch - oven-bake fish fillets from the freezer. He leaves the empty boxes in the freezer, it really gets us riled. There are only so many times you can call him back to remove and properly dispose of the empty box. If he keeps doing it, I will stop buying his fish fillets. But calling him in to do it IS beginning to work for us. He says, "Why did you call me in from the next room to do this? You're right here; you could have done it." (I hear our own words coming back at us in this). Our reply, "We called you back because it's your responsibility and it seems to be the only way for you to learn to do it right the first time."
Yes, there are times when I pick it up, still, but there are enough times when I call the kid responsible to account, and slowly they are ALL getting the message.
Basically, respect communal areas and respect other members of the household, is a primary rule. It's somewhere between Basket A & Basket B for us, depending on which kid and the circumstances. Mostly A, though.
Something we used to do with the girls' room especially - "pick up ten things."
Once ten things are picked up and dealt with PROPERLY, it is amazing how much difference it can make. Then positive reinforcement - "How much better will it look when we pick up another ten things?"
I provide a garbage bag to put rubbish in; a plastic washing tub to put clothes in for sorting; a box for books; and so on. But we don't do too much at once and we try to clear an area properly, not simply moving the mess from one room to another, which later then gets moved back as we clear the second area! The rubbish bag has to go in the bin; the too-small clothes HAVE to leave the house before replacement clothes are bought; the dirty clothes HAVE to go in the laundry and later HAVE to be put away properly.
We have a large spare room. Right now, BF2 is living in it. We used to allow each kid to move out there while dealing with their final year of high school - it gave more privacy for late-night study, more space and a chance to feel a bit more independent.
But difficult child 1 spoilt it. He crudded up the space so fast, so badly, it's never fully recovered. We made him move out back to his own room (which he shares with difficult child 3). He's a lot better at organising his own space now, but his things are too numerous and too large to fit into the space we can allow. HIs array of medieval weapons; his massive collection of Star Wards memorabilia (including huge light sabers) and all his collectables drive me crazy. But when they annoy me, I move them to his room and put them on his bed. He knows what this means - "I'm being nice. I could have thrown this away. Do not leave it in the living room again."
BBK, I think you are right to do this now, while she is young. Reclaim your communal space and remind her that her use of the craft room is under sufferance - there are conditions of neatness required and if she can't comply, then she loses it. But you might have to let her have a messy room, providing no food or drink is consumed or stored in there. This includes wrappers.
One more thing about the laundry - you mightn't have this problem with Tink, but I did with the boys, especially - they collect 'bits' of things, sticks, bottle caps, stones, plastic scraps, and their pockets would turn up full of rubbish. I keep a bucket in the laundry and empty all pockets into it.
Then there was the time when difficult child 3 started school but was still using Pull-Ups - I forgot to check is trousers for discarded Pull-Ups before I did the laundry. Have you ever tried to clean that stuff out of the washing machine? Not recommended...
Kathy, thanks for the info about this other guy. I'll have a look, do some digging. I'm always open to new suggestions and point of view.
Hang in there, BBK.
Marg