I found my smallest crochet hook works great for closing and opening safety pins when I was quilting.
I also have a tweezers handy when sewing. Use it to pull up thread from the bobbin, pick off any stray threads, pull out pins from under the pressure foot (but not yet under the needle), etc. I use the back to poke out corners as it has a rounded point.
What non-sewing items do you use?