I use the fake credit cards that come in the advertising from credit card
This wasn't my own idea. I had heard of someone making them, but drew my own pattern. It is designed so the tips just fit corner to corner on the card. (The pattern in the photo is drawn on a piece of paper.) Cut out the pattern and trace around it with a Sharpie marker onto the card. Cut the card with heavy scissors, except the circular area of the hook. Use a hole punch for that spot. Make sure all the edges are smooth, so they don't snag the yarn.
I make sure I give a couple to each new weaver I get a chance to teach. This photo is of me in my weaving studio in the garage. It's a bit chilly out there this time of year, so I decided to bring one of my small looms inside. I just started some hand towels with Atwater-Bronson lace pick-up, using some of my designs.
Have a great time weaving! I know I am!