I use Dean's facet tillering on every bow. The facets serve kind of like plumb lines for maintaining a uniform belly. They also minimize the amount of flat surface that has to be worked with flat tools, which makes it physically easier to work on a bow.
To begin floor tillering, the facet method has you cut a flat facet across the belly, and angled facets on either side of the belly. You alternate working the belly facet and the side facets to reduce weight and bring about the tiller. As tillering progresses, you begin to cut additional facets at the corners of the original facets until they belly round. (A hexagon shape becomes an octagon shape, which eventually becomes round.)
I begin to knock the corners off the facets about the time that I begin trying to push-pull brace a bow. (I brace my bows, usually 55-65# @ 25", as soon as they're weak enough that I physically can manage without blowing a disk.) By the time I first get it strung, they belly is getting pretty round, and I'm perhaps 10-20# overweight on draw. I finish the belly rounding from that point and work "in the round" from there, though I think Dean carries his facets just a little later in the process before he begins to round them.
Apex, Dean's book, "Hunting the Osage Bow", is a complete bowbuilding guide, from tree selection, to tillering, to finishing. "Facet tillering is discussed in depth, of course, but it's only one piece of book. Written in storyline prose, it's extremely entertaining as well. Not at all a dull manual. Engineering types used to scouring phone-book thick technical specification manuals will either be driven mad by it or find it a breath of fresh air. I'm certainly in the latter camp, though I admit there are bits and pieces that are cryptic as hell. (Dean did that on purpose I guess, to make us dig.) It's the most complete, exacting, and entertaining of many bowmaking books that I've owned. It's also one of the few books where I agree with nearly everything presented. In fact, of all the designs that I've tried over the last decade, I'm ever more fond and appreciative of the design presented in H.O.B.