Whip It

Whip Stitch - a very useful stitch for joining two open pieces or two flat pieces.  When done correctly, it makes a nice and neat join.  When done incorrectly, it makes a lumpy, bumpy terrible seam.  So, it's definitely worth the time to get the proper technique down!
Here's a great tutorial by Rachel from Crochet Spot: Whip Stitch


Here are some fun & free patterns to practice on:

Hello Kitty Scarf from Made by K

TARDIS by Nyss Parkes from Craftzine

Case from Little Birdie Secrets


Happy crocheting!