for the love of god brush your teeth.
Seriously though, when you start kissing, wait one second and see if the person your kissing is aggressive or passive, and play the opposite. If that doesn't do it for ya, kiss how you want to and be selfish. A really good kiss, IMO, is both aggressive and passive in turns. Pull your partners body in
your hips to their hips. Any more tips and this answer is liable to be deleted for obscenity.