Originally Posted by
louieatienza
A lot depends on your workpiece or what you're trying to cut. I also usually use X,Y at center for msot one-off jobs, or when I'm using a piece cut to rough size (about 1/8" around) that will get trimmed. For most sheet goods I'll zero X,Y bottom left corner. Zero could also be a hole in a fixture; I have a couple jobs set up with Zero at left centerline. I also did an engravong on a live edge plank that was jointed straight on the right side, and Zeroed the X,Y at top right.
For lining things up, there are some great suggestions already posted.