I did not have very nice experience with steppers and drivers. When I first built my 3D printer, I plugged everything right but there wasn't even a single move on my stepper. I started to check wire by wire with a DMM. Everything seemed to be good except that it just doesn't move. I found it pretty uneasy to debug three things together: RAMPS1.4 board, A4988 and the motor itself.

It took me a month after, when I borrowed replacement StepSticks, that I discovered the chips were faulty.

Then I went to study designing PCBs and made this useful PCB with embedded 555 acting as a signal generator for A4988 (or DRV8255, or equivalent). By turning the knob, the square wave frequency is altered and the rotating speed of motor is changed.

I find it particularly useful when I had to manage the StepSticks during a 3D printer assembly event during which everyone has problems with their electronics or mechanics. Hell!