I just wanted to share the way I've been practicing improv lately. I've been dividing it into three different parts; with only a metronome, with a play-a-long device, and along with a real recording. With a metronome is the hardest one for me, but it's very rewarding. I usually do the same tune I'm learning with the play-a-long (I use the iRealB iphone app) as with a metronome alone. Obviously, I first do it at slower tempos, then speed it up. For now I just do it in the real key of that tune when doing it with a metronome. But when I do it with iRealB I try doing it in as many keys as possible, I won't lie to you, I don't do it on every key because I run out of time quickly, but the more different keys I do it the better. (The iRealB app is like Band-in-a-box, you can do anything in any key or tempo with many different rhythm section styles). The third way is with a real recording, I do it different ways, I try to play my own solo on top of the solo I'm trying to imitate, or I try coping what the solo I'm listening to is doing (this is without ever transcribing the solo before, so I'm not supposed to know the solo). I also try combining the two, doing my own thing or coping as much as possible. To me this is a very effective way of practicing, plus it makes practicing a lot of fun. Sometimes there's a phrase I hear from the recording I really like so a pause the recording and try to transcribe it and learn it, and sometimes transpose it to all 12 keys for practice purposes. One good thing (out of many) about practicing improv along a real recording is that I can realize how much I suck compared to that real jazz giant :-), I hear the phrases he does and makes me get out of my "changes playing" so it makes me come out with real phrases, the way it should be. (What I mean by "changes playing" is just outlining the chord changes, going up and down the harmony but not really taking it to the next step, which is playing real music). By playing it along with the recording I also try to imitate sound, phrasing, articulation, overall technique, time, etc. I can't really think of a better way to practice improv. Well, the real best way is with a real rhythm section of humans, but realistically speaking no one can have one every day at home. Now, if you find a way to go to a jam session every day then good for you! Please share your suggestions or comments, or how you've been practicing your improv.