Obviously, this is concerning methods that don't require a neck jig. I'm just curious exactly how people do this. I know some say to use the tops of the frets themselves, but how exactly do you do this? If you've got one high fret, won't it throw off the straight edge the rest of the way? Secondarily, if anyone is unfamiliar, the traditional way is to use a notched straightedge along the fingerboard. Either way, would it be helpful to check the level in a few different (between the E and A, D and G, and B and E) places to suss out any humps or inconsistencies so as to adjust the truss to compensate and find a happy medium?