I have the Westalee templates, too. And I teach the ruler classes at the shop where I work. Working with rulers is like anything else -- it just takes practice. I've used my rulers on up to twin size quilts on my small Bernina.
Quilting gloves really help a ton. I like the Machingers -- buy them small so you don't have bulk at the tip of your fingers. I like the HandiQuilter sticky back grip. But I'd sure like to find that non-slip spray adhesive!
If you can afford a Teflon sheet to cover your quilting surface, that helps, too. Someone else suggested using baking parchment, like what you use on a cookie sheet.
Keep practicing and you'll get it.