The Invisible Decrease
I prefer using the "invisible decrease", especially when making amigurumi. Its simple, easy, and makes your crochet decrease look a lot cleaner!
1. Insert hook under the front loop of one single crochet stitch, then under the front loop of the next single crochet stitch.
2. Yarn over, and pull through two loops.
3. Yarn over and pull through remaining two loops.
And you're done! Easy right?