Well, I guess I would start by not looking in the mirror to find something you like about yourself, if that's really distressing for you.

I realize you have an eating disorder, so this might be a little.....inappropriate? But how about your wrists or ankles being something you like? I've always wanted nice, delicate ankles, but it's not going to happen. I like my shoulders and collarbones, and the way my biceps feel when I touch them though. Not exactly things you think of as being positive attributes.