Being an autistic person, I have a few.
-If I'm excitedly explaining something to someone, I don't think much, so there's a lot of "um... um..."s when I'm speaking.
-If I'm drinking water, soda, or whatever, if I'm drinking more than one thing, I HAVE to finish one before the other.
-I always shower at night because I hate needing to feel water dripping on my shoulders the whole day.