My suggestion would be to use some of your scraps and make a practice quilt. Find a pattern that you could turn into a table runner and then go ahead with the triangles. If you're not happy with it, at least you've had some practice and I'll just bet you end up with a wonderful table runner! Go for it. Who cares?
I have a heck of a time with machine quilting and I know that I'd get better with more practice, but sense I get so frustrated, I don't put in the time. I machine quilt baby quilts and have never yet had a baby say it wasn't nice.