I've had ADHD forever and organizing for me is really hard. I tend to lose everything if I don't keep things clean AND organized, and that can be a lot of work! Over the years though, I've found three things that help me function.
1. Get rid of as many things as possible. The less stuff there is, the less stuff there is to distract and stress. That's actually why I'm so drawn to minimalism. It is a way of life that helps me keep my life in control.
2. Define the space. For example, my bedroom currently is for sleeping, dressing, and reading. Anything else cannot be in my bedroom because it distracts from those objective. Now that I'm married there are a few more things in there, but for the most part we stick pretty closely to those things.
Another example is that when I was younger, I had a designated space for homework outside of my room. That space was specifically designed just for homework and had other distractions minimized. It was actually right by the laundry room, so that I had white noise and my siblings would usually leave that part of the house alone. In college, I did the same thing by finding a place that I can focus that had no other big distractions. Each room, closet, and drawer in our home has a very specific purpose. By defining the spaces and using them only for those purposes helps me a lot!
3. Walk through your routines. One of the worst experiences I had in college was having a roommate "help" pack my closet after I asked her not to. When I came home and found everything in boxes, I sat on my floor and cried. I felt so overwhelmed because I seriously didn't know what to do with everything out of place. I ended up pouring out all the boxes and redoing everything, so that when I moved to my new apartment (with a new roommate) that I could set up my routines.
Every time I move to a new house I do this. It is that important.
So what I mean by walk through a routine?
Let's take walking into my house after going some where. (This is probably the most important one I have).
So when I walk in, I open the closet closest to the door. I dump everything in my purse into my necessity baskets, hang up my purse and coat, and then put away my shoes.
What this does...
a) keeps stuff from getting accidentally lost in my purse
b) gives my keys a designated spot
c) keeps me from buying duplicates of things that I lost
d) keeps my shoes and coats off the floor and together
e) helps getting out the door quickly
When I get ready to leave again, I can pick out what purse I want. Grab whatever I need, and put my shoes on. It's all there. If I need sunscreen or a full diaper bag, I have it all in my necessity basket.
It's not how most people organize there coat closet, but even if I get distracted, tired or sick this routine is so solid that I never lose my keys or wallet. Everything has a place and it's easy and convenient for me to follow it. If your kid has ADHD, you can walk through it with them! The way I graduated college was I had a counselor at BYU who did this with me once a week with my homework and backpack. It saved my grades and my sanity.
So I hope this isn't too complicated and answers any questions about organizing with ADHD.