We all have methods that work for us, feel free to share your method! No claims my method is right or better it's just how I do it.
First off I only use a long string when I am working on something I am not familiar with, extra heavy, extra short, extra reflexed, extra light, extra long etc. If you are a new bow builder all bows are unfamiliar to you.
1. After floor tillering, I put the bow on the tiller tree using a string that hangs down to about where brace height would be
2. I apply enough pressure to expose any areas that are not even I try to make the two limbs match each other.
3. If the bow looks even I pull all the way to full draw weight even though it might only move a few inches.
4. I continue to scrape, adjust and lower poundage testing at full draw weight with each pull until I reach a point 4" short of my target draw length at which time I brace the bow.
5. Thats it.