I went on a "tip brand, tip shape, and shaft size research frenzy" a while back. I only may need a draw shot once or twice during a tournament, but when I need it, it is critical. I missed one of these shots once too many times and decided to do something about it.
I needed to be able to draw the cue ball back a predictable distance.
I'll save you a lot of time, I use a Moori III (Q) tip - dime shaped on a 12.5mm shaft. And I religously keep it a dime shape with a 1/2" electrical PVC cut in half about 8 inches long and 220 grit sand paper. (No eyeballing when shaping my tip!)
I found that soft tips draw the best, smaller tips draw better, and dime shapes draw better. But the Moori III S, M, or Q will all draw just as well! (Yeaaa!)
Anyway, once I found the best size - 12.5mm largest shaft you can get a dime shape on (for all around playing, not just draw), best shape (dime shape best for draw, quarter worst) and best tip which always plays the same (Moori III -Q), and a good shaping tool to keep a consistent shape (PVC), I was able to practice my draw shots and consistently draw back specific distances. (1 diamond, 2 diamonds, half table, etc.)
Chalking extremely well before each draw shot...
I shoot as level as possible with a closed bridge and place my hand all the way back on the butt of the cue and follow through so the tip hits the table after hitting the cue ball. I control the distance of draw back with the speed of the hit, although this depends on the distance between the cue ball and object ball.
Note: The problem with my old tip was that it varied in surface texture and needed scuffing as it became slick with play. So depending on the condition of my tip, I would get different draw. Now that I have a consistent tip in all respects, I get consistent results.