For those who sometimes choose the 'numbers':
If the number and calculations don't make the ball drop, then one of the upsides of the numbers is refining & figuring out precision & accuracy. It like the rings on a gun's target and the increments on the gun sight retical.
That's how you adjust the gun sights quickly and accurately. It doesn't say, "A little bit, or, a tad more." There are increments. Yet, to add....
If you do it by feel, your head makes 'measurements' in your head anyway. Unless you're guessing and it's a shot in the dark.
Using numbers can provide assistance, that's why gun targets and gun reticles have them.
Use whatever works in the end, natch.