Most of the songs i write have multiple tempo changes, and sometimes the quick transition from say 160bpm to 120 bpm doesnt sound quite right. is there anything i could do in between the tempo change to make it flow better?
Why do your songs have quick tempo changes if it "doesn't sound quite right"?
My response to all of these questions is the same: How many three minute pop songs have you written? If you can't write something simple, of course you're going to have trouble writing anything more complex.
Someones knowledge of guitar companies spelling determines what amps you can own. Really smart people can own things like Framus because they sound like they might be spelled with a "y" but they aren't.
Yeah man, cut the huge tempos changes!

You question is vague, but if you're using a drum track and simply want the beat to go slower in sections, then you don't need to alter the overall tempo, just the beat.