If we are having a Jam Session, let's jam.
I too would like to improvise better. I had started with playing different instruments over many of the submissions of the members.I too found with practice,one gets better at it. I just found the key and followed the signature. For example,in the key of G,you know to play an F# etc. We could pick different instruments and play a familiar song with participants going in and out of the melody. In other words,doing whatever the spirit leads you to do. That's jamming.
Just a thought

Bernie