Focusing Method Poll

So I have decided I need to get back to basics and examine how I'm focusing my images. For planetary I use a home made Hartman mask, but it seems to have a fairly wide focus range where the dots converge. I saw a post on CN about using slits or triangles instead of round holes I might try, but what else is there? Is it possible to make a knife edge or rhonchi grating for my logitech QC4000? I'd like to be able to know without a doubt I'm in focus. What methods are everyone using?