Sometimes I outline, sometimes I don't. Sometimes outlining makes me loose my oomph, and sometimes it doesn't. This used to scare me. But I know that even when I'm oomphless, I can sit down and put a gun to my own head and write it if I have to, so I tend to err on the side of outlining, especially for very long (over 20-30,000 words) pieces. My novel-length stuff tends to have umpty zilion subplots going at once, so if I don't outline, I'm doomed.