The Key does come down to "Do you use it..."  For our theater, Do you use it also goes to do we use it for good will and broadening of the arts.. We loan out just about everything we have to schools and other community theaters as well as local groups doing small programs etc... We have a costume room that is about 60 x 40 and yes we have hundreds of shoes and many many hats... On the hat front, we store most hats either on shelves, or in rubbermaid boxes (clear). We also hang larger peices from rope lines with clothes pins.. Our latest move was to take our fedora and other mens hat and spaced screws on an unused wall about 12 x 15 and made a very nice display that not only made it easy to find, kept them from getting crushed, but also looks cool...  As far as a seperate room for shoes, if you have it, use it.  We have two large rooms with furniture, one with set pieces and flats, one with props, one with wigs and our newest room is for curtains and cloth set dressing items.  We have decided to hang them on hangers for easy access and to prevent wringling and mildew...

This of your costume storage like your clothing storage at home ... if you don't use it, pass it along.  Keep the pieces that you'll ALWAYS use (slacks, vests, shirts, classic dresses, capes, etc.), but who in the world needs 3 Annie dresses, 24 neon jumpsuits from the 70's, and 30 prairie dresses?  (Yes, I've actually seen all of that ... and more ... in one costume storage room.)  It's hard, yes, but necessary to purge.  Same goes for the shoes.