Design by Jane Green from Beautiful Crochet Stuff.
Here is a nice Christmas tree pattern made with the granny triangle that can be used to adorn or decorate with. I think these make great ornaments and would be a nice gift as well.
These work up fast and easy making the trees great to do when you are short on time or need to use up some scraps of yarn.
You can also look up the crochet star pattern by Jane here to add an extra touch to the trees.
Recommended materials are sports weight yarn and a 3mm hook.