It all depends on how many I need to make. There's always the dilemma of "do I add the seam allowance" or not, too.
I have used heavy plastic from Joann's and my local quilt shop to make templates. I try to buy the plastic that can be ironed. I draw around the shapes so that I have a seam line and then I cut approximately (by eye) 1/4" away using either a rotary cutter or scissors. I have also drawn the shape on freezer paper and cut approximately 1/4" away.
If I'm going to need to make a lot of the same shape, I usually look for a commercially made template - Marti Michell's come to mind.