Go to E-zone and do a search - it's been very well explained a number of times. I did it and didn't notice much differance between just timing it fwd and using a meter, except the amps go up a little so the batt and esc were slightly warmer (and 45 secs less runtime) and the motor was slightly cooler. I started at 12 degrees and ended up at 25 degrees. 95% of timed AF's land in the 20 - 25% range. Each tick is 5 degrees, and to advance it you look at the endbell and turn it CCW.

BTW I'm at sea level and using an 8 cell HRSC 2600 pack with 4x4 grips.