A quick way to rough in the door location that has worked for me, is to tape sections of wooden paint stirrers on the door frame/opening at key points. Then locate and bolt in the door tight enough to stay in place, but easily loosened when making the final adjustments. If you are lucky, after removing the stirrers, the door is roughly where you want it. At least it is a good start point. It doesn't always work, but when it does it saves a considerable amount of time. Aligning doors from my experience and from what I have read is usually painful and a little bit of an art form.
