Hi Ron, Hy's given you what amounts to some coarse rules of thumb. If you are interested in precision (to avoid wasted time), I suggest you become familiar with and calculate your critical focus zone size, and measure your focuser drawtube travel. The 3rd important variable is your motor counts per revolution (focuser motor). You don't want to set a step size larger than the CFZ (otherwise, you'll just jump over best focus). Too small and you'll waste time walking through several measurements in the same CFZ.
The CFZ topic and calculation (don't be scared by the math...it's easy enough) are covered here:
Some minor time spent reading another related topic can help too (starting at the link):
You'll then be in position to set that step size properly and with confidence that your V curve will be sized right. In an ideal world, the step size setting should be automatic (based on other system parameters), but it's not too hard to set manually. You'll also have a better handle on how seeing affects needed precision.
Good luck and happy readings, Doug