My main use for fusible interfacing is an odd but practical one: I iron it to my tissue paper pattern pieces (for patterns I use a lot, such as purses/totes, dolls, clothing - you get the idea). It makes them last forever.
Other uses are for:
- interfacing caps, hats or hat bands, collars, pockets and sleeve cuffs (BUT, be sure to cut the interfacing piece's seam allowance back to 1/8" or 1/4", not the full seam allowance to reduce bulk while retaining shape)
- interfacing purses (so they stay pretty much erect)
- interfacing straps to purses and totes
- interfacing flat ornaments, keyring fobs, etc.