I've put blackout curtains in her room, hue light bulbs, led strip lighting with a remote control underneath her bed as she's got a high sleeper with a sofa bed, she has an echo dot so she can completely control the entire environment in her room, lights, music, sounds the works.
I got a very cheap exercise ball to bounce on, a boxing ball to punch, she stabs cardboard boxes when she needs to. She has noise cancelling headphones to use sometimes.
She's always done art to help express her feelings and her special interest is computer stuff so I got the xp pen artist and an old version of Corel painter for her birthday, we made an art wall to display her best work (she asks that I'm honest!) and this week she has been writing loads and loads of poems about her feelings!
I'm so proud of her at the moment!
In the past we've done token systems to help teach about appropriate roles and other people having needs so I get 7 tokens, she gets 7 and her stepdad gets 7. She can use her tokens to 'buy' something from us such as getting her a drink or helping her with her shoes (things she could do herself), when she ran out she had to do something kind for us to earn tokens back. It only took a month of doing that before she stopped being really demanding.
We have also had secret signals, she hooks my little finger in hers if she's getting overloaded and I agreed when she does that then we have to stop what we are doing and give her space and she became prepared to deal with waiting then for us to say goodbye and finish what we were doing because she knew we would accommodate her need to withdraw...
She's a lot beyond that now but one of the main things was realising that she was trying to be so controlling because she felt overwhelmed by things we just thought were normal and what we were actually doing was expecting way too much of her.
She still has meltdowns, she's got significant MH issues as a result of the years of having unmet needs but actually how she is at the moment is the most content within herself that she has seemed in years.