Personally the things hat have helped me out the most include:
Notetaking -
I have grudgingly come to the conclusion that my memory isn't....good, so I just started taking notes on everything and anything that I learn.
Active learning applied to life has helped me a lot, and being able to have one software for everything I need to remember helps too.
I switched through a few, but I'm settling on ObsidianMD for now on account of markdown apparently being the most accessible for transferring to different software if the need ever comes.
Developing an interest in mental health topics -
I find that by researching more about mental health and things I've been diagnosed with, I'm more understanding and less stressed out about the things I've done in my life.
A lot of people look at their ADHD diagnosis and try to ignore it, but for me, I need to have an understanding of how my body and brain works in order to cope with it properly.
With that said, I usually look up things on ADDitudemag and books that I find on sale.
Understanding self-improvement isn't necessarily productivity -
This was one of the bigger things in my life I had to learn to understand, and to this day I'm still struggling.
Basically, just take the productivity rat race and put it in a corner for now, and start looking at yourself as a person and decide what will help you out the most.
For example, cleaning doesn't have to be productive, it just needs to be done so you can walk from point A to B.
How about you? What helps you the most?
What helped me the most was finally finding a diagnosis that made sense of my issues. I had male friends who had ADHD and I did not see myself in their symptoms. Finding out that women exhibit ADHD differently changed my life. I'm high functioning, but it's always with such great effort that I'm often wiped out at the end of the day. Now I understand why.
As other people have mentioned: the biggest help has come from notetaking, writing things down. I have a magnificent memory, but it's all packed tight with strange and arcane information that doesn't help me when I'm at the store and forget to remember what groceries I need to buy or that I'm out of cat food.
I've also learned that the act of physically writing things down on paper is even more effective for me. Digital devices (and I'm a computer programmer) are too easy for me to fall down the rabbit hole with. I'll pick up my device and I'll do 10 other things I want to do on it other than record my note! I've also learned that the fancy planners and stickers and washi tape are all big distractions and lead me to hyperfocus on the prettifying and not give any attention to the actual information dump I need to do. Even the choice of writing implements (fountain pen? Sharpie? pencil?) can derail me, so I've picked a common pen for my note-taking that I can easily replace. All the GTD (Getting Things Done) and Bullet Journal stuff was nice for giving me the idea of a structure, but again, the details of the methodology tended to block my flow, so simple bulleted lists. Everything gets a date. Bullets for ideas, thoughts. Checkboxes for things that need to get done. Small, do-able steps, so I feel a sense of accomplishment at finishing something.
Also, learning to forgive myself was also key. I can't be perfect, I can't always do everything right the first time, no matter how much research my hyperfocus makes me do. I don't have to finish every project; I'm allowed to let it go. On other projects, if I make a little forward progress, it's something worth celebrating, not castigating myself for not finishing right away.