I am a bit burned out on the usual chord progressions that I can get my band mates to improv to. We usually do the usual I-IV-V blues thing, the "play over an E-minor chord to you puke" thing, and some sort of I-II two chord vamp for a while.

I would like to be able to suggest some new ideas. I don't really want to just pick a known song to use because then we all start trying to play the song and I think some of the creativity gets overlaid by the compulsion to cover the tune.

What can you suggest as additional chord changes that would be good practice to play over?

get a fake book/ real book and learn the standards - they will have all the changes you need

Yeah I'm in the same boat, I'm slowly picking up new ones as my guitarist throws them out there.... I'll be watching this thread closely.

We did a cool one last week that was C-B-Bb with a pre-conceived hook that brought it back around...It turned out real well...I've been listening to it all morning.

We also do a lot of 2 chord stuff like I-IV or I-IV or I-ii. I'm finding any combination of I-IV-V works like I-I-IV-IV-I-I-IV-V. You could also just lay down a really funky 1 chord deal and go crazy with it.

+1 to fake books.

IMHO it's usually way more fun for the players than the audience when you jam or the same chords for a long time.

At the very least, I would pick some actual songs to jam to, if only the chords. Follow the jazz formula for structure: Play the song correctly, then improvise /trade solos, then return to the head, so you learn to improvise in a way that has form and context. Also, play the whole song : go from verses to choruses to bridges etc...to give the contour to the jam.