1) Tie your yarn around the washer or d-ring and insert your hook.
2) Yarn over and pull through, then chain 1.
3) Insert your hook into the center of the washer and yarn over and pull through, yarn over and pull through again to complete a single crochet.
4) Repeat step 3 until the entire washer or D-Ring is covered.
5) Slip stitch to join the 1st stitch of the round. Fasten off and weave in all ends.
Video tutorial | How to crochet around a washer or D-Ring.