only actually toss out strings/threads, frayed little bits...
Just as an FYI - did you know that some art quilters take those strings, threads, tiny little snippets and after sprinkling heavily on one piece of (I think it is called...) Solvy. (Washable stabilizer) Then you top that with another piece of the stabilizer, and do some heavy free motion quilting with a variety of threads, wash the Washable stabilizer away and voila you have a really, really, really scrappy piece of "fabric" that can be added to whatever you choose. I haven't tried it yet, but it is on my list. First I have to find the pattern book that I have that I read this in, and I can't even do a search as I can't remember what that technique is called. PS - I save all my scraps as I do art, mini, scrappy, applique. Just haven't found my nitch yet. Then again, variety is the spice of life!