Other than the usual nail-biting, I also bite the edges of my fingers themselves like if the skin is uneven on either side of the nail. Kinda gross and trying to stop...

I scratch my chin a lot when I'm nervous about anything.

I guess I also eat kinda funny. I used to be worse about it but often I will eat the meal in portions. Say I have a piece of chicken, mac n cheese, and green beans. I pick one of the three and eat it entirely before I allow myself to touch either of the other two. I will drink if I get really thirsty but generally I only take a drink between 2 items of food. But I normally drink a lot once I'm finished