I took the advice of a very good Bowyer one time and the first place I start with a limb bending is the middle 3rd at floor tiller. Once I get pretty close to the draw weight I'm looking for with both limbs being consistant in bend, then I move to the tiller tree. I will worry a little more with how the inner 3rd is bending at that point, but I will always have a good reference taper prior to starting. As already said, regardless of how much fuss you spend measuring, you will still end up some place else, but without some reference to start with, the wood takes too much stress trying to point it out for you.
The closer you can get to the final dimensions upfront prior to bending, the better your result will be. I know thats easier said than done but building a lot of bows using the same design you get pretty good at just feeling the weight of the wood and knowing how to design the bow.
Art, that's a good tip on scraping at brace. I came very close to cutting a string watching it unravel like a time bomb ready to explode. It didn't, but I figured out real quick to change my direction with the scraper. If I'm not mistaken the string has more tension at brace than at full draw not taking much to put you into a bad situation.
