Best tuning method for Pololu A4988 Steppers

I've got my prusa i3 all together, firmware setup, and everything homes and moves as it should. Now its time for calibration.

I was going to follow this procedure: http://reprap.org/wiki/Calibration

But then I got to Motor calibration. Seems they want me to just run the motors and adjust the pot on the stepper while running it back and forth until it is noisy then go up an 1/8 a turn. Is this sufficient for the A4988 steppers? Should I do this with the motor loaded/unloaded (belts off the pulleys).

Additionally, this document: http://reprap.org/wiki/Pololu_stepper_driver_board

Makes it sound as if I should connect my ammeter in series with the motor and see what current is pulling and adjust it appropriately.

The most accurate way is to use a meter. I'd venture to say most do not and adjust them by hand. I've put a meter on them to tune but by and large I do it by hand, listening to the motors, feeling them for vibration and watching the calibration prints for missed steps. When I start I turn the pot all the way anti clockwise then clockwise 1/8 of a turn or so. I do this with the printer fully built and with the extruder loaded with filiment.

Thanks, that's the method I'm going to go with. I think that's the best way to do it because you are tuning it for actual load unless there are mechanical issues that are putting excessive load on the motor.

Consider that there will always be things like filament binding up into the extruder (slows the X on an I3) or crud on your rails. The nice thing about a meter is that you can decide that 0.18V works, so I'll go for 0.20V to have some margin. Doing this by hand can be a pain. The tiny pots are not ideal mechanically. If you were going to do it by pot turns a 2 turn or 10 turn pot would be a lot better. The cost of that pot would make the cost of the board crazy.