A tool that most knitters have in their little tool boxes and bags is a row/stitch counter. This keeps track of your rows or stitches so you are not forever going back and counting out what you have just knitted. It is designed to fit over the needle, so that it does not get lost while you are knitting. This works great on straight needles. Not so great on double pointed needles (dpn’s). While, yes, it fits, it will also fall off the end of the needle as you work your way around.
I thought this was an original idea, but the more I think about it, I’m sure I have seen these little counter gizmos with a plastic loop for attaching to your knitting. But I turned my counter into a stitch marker. So it can happily zip around the circle of a set of dpn’s.
Now I don’t have to keep fumbling with the little thing and my knitting.