Some of the shots I always enjoy seeing here are those of "babbling brooks" where the water flowing over the rocks has a soft "silken" appearance. Even though everything else may be in sharp focus - the water flows over the rocks in a soft silk-like fashion.
How is this done? Is it by exposure settings? Or is it done in during processing?
Long exposure is the way to go, but you also might try long multiple exposures - gives a bit more of a punch to that silky flow.
I believe our Les Maclean has posted some examples of this technique in the past.