Video tutorial from Jen Best of Beaker Button showing you how to make a crosswheel Dorset Button, the easiest Dorset button to make. You will need a closed ring, a length of strong thread or sock yarn 100x the width of the rings diameter (so a 25mm ring will need 2.5m of thread), scissors, and a blunt needle. See https://beakerbutton.co.uk/
for more Dorset button goodness.