I do little things, I guess, that ultimately make me feel a little better. I do wish I was more active doing good deeds.
If a cashier gives me back extra change accidentally, I give it back.
I will stop my car for animals to cross the street. (only if safe, of course)
I can remember this one time, though, that I went to a nice restaurant, but I ended up not liking the food I ordered. So I asked them to put it in a bag for me to take home. However, going home, I realized nobody was gonna eat it, so I stopped to give it to a poor man in the street.