One of the basics amigurumi technique is the increase. To increase single crochet is used in all amigurumi patterns and is very easy to do!
The US abbreviation for this technique is INC
An increase means that you are going to do one single crochet inside the stitch, plus an additional single crochet, having a total of 2 stitches.
If you don’t know how to single crochet, click here.