If you're sauteing larger pieces of mushrooms rather than slices, start with a very hot pan some fat and NO SALT. Put the mushrooms in the pan and saute them shaking the pan. The will brown before the release their water. If you add salt or crowd the pan, all bets are off.
For other situations, as others have said, yo have to cook off the liquid and brown them.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan