I have many mini handspun yarns, experimental things that I abandoned on the wheel before they achieved enough yardage to even make a hat. They end up in a bag and become my Grab & Go’s.
Before running out the door, I grab a ball and some knitting needles or a crochet hook so that wherever I am, waiting for a subway train or whatever, I have a creative project. I spin my yarns in a thick & thin style (I want them to look handspun!) so they don’t conform to most patterns, but all I need is a crochet hook that works for the largest diameter of the yarn, or larger, and it will work. In the photo, I’m using a hook much bigger than needed but it’s working.
The main thing about my Grab & Go’s is that I don’t know the yardage so I have to make something in which small and unknown length is not an issue, and neither is gauge.
For crochet, it works to make a mandala because you can stop at any point in the pattern. Take a look at Mollie Makes Magazine’s post on mandalas HERE.

For knitting, I tend to make little mats using the linen stitch, a stitch that requires larger needles than the yarn so the thick & thin character of the handspun isn’t an issue. Making a rectangle (or square, if the yardage is less than I guessed) with linen stitch gives me a little mat that looks like it was woven and I use them under my plant pot saucers or as trivets. Purl Soho has a nice, simple linen stitch tea/hand towel idea HERE.
Cheers!