When I get 6" to 8" of tip movement I switch to a short string and brace the bow 3" to 4" high. This will show you how the string tracks and the limbs line up. If things are off I make corrections(heat&clamps)then try again after 24 hours of cooling.
Once you are at low brace and everything is OK you can tiller out the bow as if braced normally. When I got out to 10" to 12" of draw length I go to normal brace height for the rest of the tillering process.
While the bow is at low brace I use a tiller stick to about 8" or 10" of draw and check the limb's bend with Eric's Gizmo. Usually after that, if everything is good, I can tiller out the bow without the use of aids but sometimes, even near full draw I will check the limbs with the Gizmo just to be sure my "eye" is still true.