Technique depends on what type of terrain you are on. I pretty much do what wardy suggest when it possible to go that fast. Keeping the knobs clear makes life a lot easier. Brand new soft terrain tires are also worth their weight in gold in some slippery spots.
Where it's not possible to go that fast, I often do as lococd suggests. Using the clutch for more precise control over rear wheel traction can help also.
One section on my local single track that gives me a lot of pleasure to get thru clean is a very slippery, muddy, rooty off camber on a slight hillclimb. The rut/line leads straight into trees in many spots, and the only thing that seem to work is standing up the whole way - if you have to dab, 99% of the time, you end up having to get off and push - being very conservative but constant with the throttle, and being able to balance well, as for several hundred feet both wheels are sliding down the off camber a foot or so for every foot forward. Ie, have to oversteer carefully.. Dunno if that would help anything in most places, I've never seen anything else quite like it.
Btw, Taraker, have some feelings for us lowly modem users will ya? :) That bloody thing took a minute to load for me :(