Tim-

You're right there's no need to level it in order to plane it true. But that's how I do it too. And I think it is faster than you and Gumphri's method with the winding sticks since you don't have to spot true where the winding sticks are in order to get your lines on there so you skip that step.

Jon--

Bottom line is that you can either do winding sticks as Gumprhi said or use a level as denton4th said -- either way works well to get your lines on there for planing the top into a, um, well...plane.

Or try Rays strongarm approach which might work for you (but not all of us are as "persuasive" as Ray).