Assuming that we are talking about skiing the Mid-Atlantic during a typical winter, how often (or after how many ski days) should skis be tuned to perform well on ice? Any other relevant maintenance besides having edges sharpened?
I will debur my edges using a pocket tuner before an icy day. While my edges may be sharp overall, I've found through experience that I can notice grabby spots when turning on ice due to burs from hitting rocks, snowboarders, etc. The deburring seems to help.
I ski 3-5 days per week (ok - 3-4 nights & 1-2 weekend days)... While many seem to disagree - I give a wax job every week or 2. But - the edges only get hit 2-3 times per season. Reason being is that I have found that in my personal skiing - when I go from skiing on dull edges to sharp ones, I ski much better than if I skied sharp edges all the time on icy days. Something about being forced to be more dynamic, early in the turn, etc....
A stone is always in my ski bag for de-burring also.