When you accidentally drop a stitch in garter stitch, it’s easy to pick it back up!

First, take hold of your stitch.

If your stitch has a bump immediately below it, bring the first horizontal strand of yarn through the loop from back to front.

If your stitch has a flat space immediately below it, bring the horizontal strand of yarn through the loop from front to back.

You need to continue alternating between pulling the loops through back to front and front to back to pick up stitches in garter stitch.