if there's a sale on fresh mushrooms, I'll stock up and either dry the excess or saute them to freeze.

removing the stems and using them for stock is the best way I've found to get a good broth... or get dried shitakis from the oriental food stores - lowest prices around- and then use the soaking water for soup. you do need to fool around until you get the right strength broth... too overpowering if not done carefully.