While I'm only a beginner, I found that matching my points was easiest when I stuck a pin straight through from the back of one point, and through the point of the matching one. I could then line up the rest of my block for sewing, and pin the rest of it and the points didn't move.
Here's a pic from some other gal's blogspot showing you exactly what I mean:
http://3.bp.blogspot.com/-99e7mKVU19...0/DSC09667.JPG