Warped Fabric
Sometimes fabric that has been stretched will warp after a while.  This can be avoided by using cardboard-backed foam rather than using plain cardboard to mount the fabric. It could be warped by being displayed in an area of high humidity. Once a needlework piece has been warped, the only solution is to unframe it, restretch it, and reframe it.

Cleaning pieces with beads and special threads
Dry cleaning is not recommended. Needlework should be cleaned using mild soap and cold water;  then air-dried on a towel.

Floss Bleeding
If the dye in the floss being used runs, it is recommended that the piece be continually rinsed until the water runs clear.  Remember, that once the piece has dried, the color will be set.