There are two fairly easy methods for creating a ribbed edge with crochet. Crochet ribbing #1 describes one method; this pattern shows you how to create a ribbed edge horizontally, using front and back post stitches.

It is a very versatile pattern as it can be used to start or finish an item and it can also be used on its own to create a whole item just with ribbing! Stripes can be included to add extra interest to your ribbed edge. Any size item can have this ribbed edge.