One idea I use, I attach my binding before I quilt, and that is how I get all the points OK. I make it wider, and then only quilt to the edge of it.
Then after I take it off the frame, I fold it back to the seam, and cut the backing and batting to the amount I want (1/2" or 1"), then I flip it over and using the new cut edge, I measure and cut the binding long enough to run under with a turned edge.
I don't like putting on bias binding, and I find doing this gives me a good edge for putting on the quilt frame, and then I get my points were I want them.
This is the only picture I could find - that part that looks like a narrow border actually becomes the binding when the quilt is compelte. I cut it at 2.5" wide and I trimmed it after quilting so when I turned it over to the back, each side had about 5/8" showing. But that way my points were fine and squaring up was easier, and I didn't have to worry about any edge seams opening up. The important part is not to quilt into the part that will become the binding.
I know this quilt does have a border, but since the border has points - the theory is the same.