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?