I use masking/painters tape to keep bias edges from stretching.
When I'm working with small pieces of fabric and small templates, I sometimes use scotch tape to tape the fabric to the cutting board and then tape the small template on top. Really stops fabric/template from moving.
The most unusual thing I use I got from my gynecologist. When they do a pap smear they use a long wand with bristles on one end - like a very, very long eyelash applicator (about 6 inches). It is flexible and can get into every little nook and cranny when I need to clean the bobbin area of lint. I just asked my OBGYN for a few - after explaining why - and she gave me about a dozen. Turns out she and her sister sew/quilt and she now uses them on her machine also.