I leave the tips wide(3/4" - 1") until after first brace to see how the string tracks. If everything is OK I will shape the tips and add overlays. If not, a little wood can be removed from one side or the other to help line the string down the bow. The bow has to be under tension(braced) before you can tell how the string tracks. I do the same with the handle area. This can eliminate heat bending or straightening sometimes.
For heat treating, anytime after first brace. If, while tillering you notice she's taking some set, you can heat treat again. Sometimes I'll do this as the last step before shooting in and adding the finish.