Drinking tea or milk is a good idea, I also like to have a glass of fruit juice. If you sip it through a straw it lasts longer, and it feels like you're savouring a treat, which is what I want when I'm bored or depressed. Also, sometimes I'll put some vanilla and a little sugar in a glass of milk and sip that, which is nice because it feels decadent but isn't very caloric.