[tylerxfury]

i must agree with the post above me
if your main song is in major, go minor
if its minor, go major, or for a different contrast try diminished or 7th chords
i like to make my rhythm scheme completely different from the rest of the song as well,
whether it be rhyming pattern or drums changing to half time feel
as long as the bridge fits a turning point or other necessity to the song and is in a complimentary key, you pretty much cant go wrong
best of luck in your writing =)