When I have to do difficult things, I reward myself with a treat afterwards. (i.e "I have a doctor's appointment but at least I get ice cream afterwards!") Obviously, a treat can also be free. (Reading a chapter from a book you like, taking a walk, chatting with a friend, listening to music, etc.)
You can also plan out your outfit the day before. "Everyone is going to be soooooo jealous when I show up in this fit." Depends on if you like clothes like that or not.
