I'm no expert but find I have much better control and confidence if I do this while standing (knees bent to lower my CoG and sometimes to somewhat 'ratchet' the crank, as in not necessarily pedal all the way around, sort of go part-way bring the crank back and part pedal again, weird but lets me feel in control and somehow helps me keep a straight path).
But generally I don't like doing them on the trails I ride because I'm somewhat already winded by the time I ride to where they are and if I have an accident I'm quite a bit away from being able to get to my car or to help in a reasonable fashion. If I break body or bike I'd be in pain and pissed and I'm too heavy for anyone to toss me on their back and haul out to civilization.