Ribbing

Dear users, dear authors,
how do you crochet, knit, or knook ribbing?

In knitting, ribbing alternates between knit and purl stitches.
Classic ribbing alternates between 1 knit stitch and 1 purl stitch, as used for cuffs.
On the wrong side rows, the stitches are worked as they appear—knit the knit stitches and purl the purl stitches.
However, you can also vary ribbing by knitting 2 knit stitches, 2 purl stitches, or 2 knit stitches, 1 purl stitch.
You can offset them at regular intervals to create a diagonal pattern, or you can work ribbing horizontally by, for example, knitting 2 (or more) rows in stockinette stitch and then 2 (or more) rows in reverse stockinette stitch. 

Crocheting a rib pattern is actually quite simple.

Using the yarn of your choice, make a foundation chain with an even number of chain stitches and alternate 1 front post double crochet and 1 back post double crochet.

Just like in knitting, you can stagger the post double crochets to create diagonal patterns.

When crocheting, however, keep in mind that this uses a lot of yarn, so you should allow for about 1/3 more than for plain crochet.