You can do what I like to do sometimes if I'm by myself. Put the Eric Clapton "Blues" cd on and play along with Eric. Most of the songs only have 3 basic chords that I can take and improvise and just make solos and play along with Eric.

By the way it's a really good cd. It a 2 disc set (one studio blues and the other live blues). It's got a lot of good classics.

Try that, it might help.