i did my first mount completely free hand. granted it was on a pair of skis that I had already drilled completely through to mount on a wall. It was a super low snow year at Sierra and I didnt want to be skiing my brand new skis so i took those suckers down and filled in my drill holes with some jb welds and epoxy.
anyway, i measured a bunch then put the bindings on the ski where they should go and sent a tiny paint brush with a bit of paint through the binding screw holes to mark where i should drill.
then i sorta just compared the size of the binding screws to the drill bits my dad had laying around until i found one that i thought would work.
So i drilled the ski and drilled until i felt the core and went juuuust past it. Mind you this was with a standard drill bit that wont keep you from coming through the ski.
Anyway, I got the bindings all mounted up and when i measure at the end i was off by only 1-3 millimeters which i feel is pretty good considering how janky i had it set up.
I ended up skiing those bad boys for another two seasons (hard seasons too if i might add) until they finally exploded on me.
It got me started on my path to becoming a ski tech and getting to use all these jigs and specific drill bits so Id say mission accomplished
TLDR its super doable, if you have an old pair of skis that dont really matter anymore i say go for it.
I love bad bitches, that's my fucking problem.
I'm just going to beat it all day long for months on end.-Aidan_G