Down shift and steer towards the skid, pumping brakes really only insures that your brakes don't lock up.

 

Not sure about downshifting, wouldn't that disturb the traction and start skidding? I agree with the steering into the spin though. The common tendency is to steer out of it, but that just keeps you moving out of control.

 

yea.. shouldn't shift when going downhill.. if down hill has a turn.. brake then turn, never at same time (same for shifting). Apply brake lightly.. get winter or all-season tires...

and... no1 has mentioned this so far..

if you live in place where they never remove snow.. snow chains might be an option (except in Chicago where it's illegal - but then chicago does good job in removing snow neway..)