One process I try to stay open to is mistakes. As in, playing out a chord progression and messing up, but liking the mess up. I quickly jot down what I did (wrong) for playing around with in a couple of minutes. Or sometimes, if I'm recording, I'll grab the errant clip and stash it way at the end of the timeline. Actually, I've started to dragging clips right off to a folder in the browser. This is a new way of working, don't recall exactly when Sonar started supporting it, so I'm trying to work it into my routine.
Reading about the successes with BiaB above made me give it a look-see, that process sounded neat and fast. But after a while I realized I wouldn't be making mistakes, wouldn't be "close enough" to the notes (fingers on keys or strings or holes or skins), so that route won't fly for me. I don't want fast that bad.
I've dabbled with the matrix view. Kind of like it sometimes. I can use some of those clips I've dragged off (mentioned above) and mash them together. I don't view matrix as an end product. Well, mostly. But it's a fun creative.
Related to matrix, a trick I've found for playing around is to drag a clip into an empty Dim Pro instance. Then I can instantly transpose it, from the keyboard or from Matrix view. I'm using DP as a sampler, and I know there are better, but it's right there and it works.
I do a lot of extended jamming to get ideas, sessions lasting from ten to 30 minutes. Sometimes they're fun, sometimes they're pure drudgery, but a writing teacher told me once to "write every day, even if it's crap" and that has worked for me. (It's a funny thing, I can look back at these jams and see "periods" in my life. Funny or creepy, sort of like
Krapp's Last Tape.) One thing I've learned, or--more like it--come to terms with over the years is to jam to a click (metronome). I know, I know, I hate it sometimes too. But I've found that an idea set to a "legitimate" beat is way easier to transpose to a piece than one that floats around. So the steady ideas get worked on and move forward, while the ethereal ideas just sort of stay that way and take up drive space. I jam to a click, it's a trade-off.
One more idea (for today at least). When I "sandbox" or improvise or jam or whatever, I typically use two or three soft synths at a time (controlled by one keyboard or the midi guitar), to get a BIG sound. Well, maybe not only big, just a lot of frequency, lows, highs, breathy, choppy, ethereal (_that_ word again), cinematic, whatever. It's like hearing an orchestra (in a vague new-age-y sense) and I think it helps the juices of creativity. Sometimes I use reverb, sometimes not. No reverb encourages faster articulation, I find, and different results.