I use my table saw, but I tilt the blade to the angle I want. Then I attach a fairly tall auxillary fence to my saws rip fence. I hold by neck blank vertically against the fence and then I clamp a guide board perpendicular to the neck blank, that rides on the top of the auxillary fence. I raise the blade up a little at a time, and make several passes.
If my blade isn't tall enough I finish with a hand saw, but for my LP neck the blade worked out to be tall enough. (pretty extreme headstock angle)