I’m also struggling with ADHD and actually committing time to self care and “cultivating an aesthetic”. That being said you don’t owe a particular look to anyone. Of course if it’s what you want for yourself that’s fine, but just know we don’t owe society passing. I also find the usual, mainstream parts of the internet largely unhelpful for things like makeup and fashion. Part of that is my anatomy (very pronounced brow bone and “sunken” eyes) but a big part of that is the “rest of the fucking owl” problem. People on the internet honestly do a pretty shit job explaining stuff most of the time. In my experience the best way is to just experiment.
I know clothes shopping in public can be a nightmare, but thrift stores are for the queers, and most town have at least one decent store. Thrifting is great because you can experiment a lot, with often odd items, but spend very little. Once you start to develop a sense of what you think looks good on you using the weirder items, then you can begin to consider some targeted new clothing purchases. Some good basics and a couple high quality statement pieces can go a long way.
For makeup the hardest part for me was finding the line where the wing for eyeliner wanted to land. This just took time, experimentation, and the odd friend doing it for me to see how it looked done by someone with a more deft hand. Eye shadow was fairly easy for me personally with just a few general rules. Lighter color near your nose, a darker shade toward the outside of your eye and along the crease of your lid and the eye socket, blending a mid tone between the two. Something a bit shimmery over the top and maybe a few well placed dots of liner, or some thin lines near your tear duct to play with the size your eyes appear to be. I really only just started using foundation, but I try to keep it mostly to my chin and jaw as that’s where you can see some dark ends of hairs when I’ve shaved. I’ve got naturally fairly rosy cheeks, but I’ll sometimes bring the foundation a bit further up my face and then do blush.
That’s sort of my “simple” look, and is really the only thing I practice right now. My goal is to be able to do that within 15 minutes, and I’m sitting at about 20-25 right now. Similar with fashion. When I’ve got a well curated capsule wardrobe, picking an outfit doesn’t cause as much executive dysfunction. Basically I’m looking to make the task of self care less daunting and thus more likely to happen. I still want to get medicated for ADHD as I think I’d become unstoppable, but in the mean time this is helping a bit.