There is a poor mans method, and basically you run a load of G00 moves back and forth on one axis.
G00 x0
G00 x5
G00 x0
G00 x5
and keep on looping. As you adjust the accelleration values, the servos will start to stall. Now adjust your geckos, to stop the stalling. Not too much gain that the servos "sing" while stationary, but too little or you will have a "spongey" response. Adjust accelleration again if you need to, and double check settings on gecko. You can check again by using a smaller step eg, G00 x1, G00 x0 on a loop, or perhaps a larger step.
Hopefully there is a more technical method, but that's how I do it!
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)