Play new purchases several times on the decks, usually on a Saturday and Sunday morning. I then file them in the 'ready to burn' pile.
Personal CD compilations are a great way to listen to them, I've made so many now that when I get an earlier made one, I hear a track that I'd completely forgotten I had!
I do have a box of special favourites that get a spin on the decks when the mood takes me, usually when I'm at home alone.