I have been spending some of my time making squares out of partial skeins of yarn that I will make into baby afghans for charity. I'm not sure if this is a formal pattern somewhere or what but here is the basics of how I make these squares;
Using a 5mm hook and worsted weight yarn, chain 36.
Row 1: Double crochet in the 4th chain and then dc in each chain to the end, Chain 2 turn.
Row 2:Skip one dc and dc in the next stitch, then dc in the skipped stitch. Repeat until the last stitch and dc in that last stitch. Chain 2 and turn
Row 3: DC in each stitch.
Row 4: Repeat row 2.
Continue until square - for me that is 15 rows (I like to end on a DC row).
Here is a picture of a square I have made using this pattern: