A couple of patterns (with tutorials) that use double crochet –
Granny Ripple Blanket
Granny Square Blanket

You can see the slow-motion playlist here.
You can see the entire Crochet for Knitters series here.

The yarn I used for demonstration is PaintBox Yarns Wool Mix Chunky. The crochet hook is by Boye.
The scarf on the mannequin is Bay’s Edge (not my design), more info here.