My rule of thumb is to get the edges tuned once a season (I clock ~40 days), usually after the last of the rocks is covered up by the initial snow. If one skis less than that, it's possible to get away with every other season, but keep a gummy stone to deburr the edges as needed.
If anyone has any methods to reliably grind edges at home, I'd be interested. I have one of the edge tools and a bunch of files, but I basically destroyed a pair of skis (thankfully an old crummy pair, put to new use as part of an adirondack chair built from my busted skis) when trying to get it right. Considering a local shop will do it for $40 / pair, that seems like a better use of my time. Still, I've got that DIY itch to scratch about this and haven't seemed to get it right.
A local shop might as well make things worse if they do not care too much and give your skis the standard treatment (e.g. different angle than before).
Once you have a good edge, it's kind of similar as keeping a knife sharpened. No need to really grind every time, a fine polishing after skiing for a day is more than sufficient and makes your edges last a long time.
Been using tools from here for 10+ years, they also have informative instructions: https://www.tooltonic.com/
Professional chefs get their knives sharpened once or twice a year, depending on how often they use them. They hone their knives before every use. The honing rod that comes with your knife set is there to realign the steel molecules along the blade edge. Sharpening your knife removes metal and creates a new blade edge, which you have to hone frequently for it to stay as sharp as you want it.
I wonder if the ski tech person was using terminology correctly but the skier/blogger didn't quite understand.
Not sure how you managed to destroy a pair of skis? It's mainly just to clamp the file onto a metal piece with the correct angle and grind away. Normally I put pen marks every few cms on the edge before I begin, then all those should disappear and I know I've grinded about the same all places.
Or with a tool like Swix TA3008 it's hard to do wrong. Maybe need someone to set up the base angles, but then you can use it to touch up for years.
There's tools that can measure them. A low end is just a piece of metal that fits the edge with no light coming through. You can use a true bar and look with a loop or magnifying glass.
If anyone has any methods to reliably grind edges at home, I'd be interested. I have one of the edge tools and a bunch of files, but I basically destroyed a pair of skis (thankfully an old crummy pair, put to new use as part of an adirondack chair built from my busted skis) when trying to get it right. Considering a local shop will do it for $40 / pair, that seems like a better use of my time. Still, I've got that DIY itch to scratch about this and haven't seemed to get it right.