Wax - the wax that manufacturers use is kinda known as transit/shipping wax. It is just buffed on and keeps the edges and base protected and looking good on arrival. So it is not an ironed in hot wax which is the best. Wax should not be thought of as just a speed thing. It gives u glide which is performance including turns and spins and protects the bases. If u spend a fulll day out on artifical snow or "aggresive" snow u can run the wax off the base in a day. Waxing and Not scrapping it off will just leave u with bumpy wax splotches and u won't have as smooth a ride. Good to do every 2 -3 weeks depending on what kind of skiing...see tuning below
Tuning Twin tips - Ask the shop what the original tune / spec is for your ski. Most twin tips are 1 degree base and 1 degree side edge. Of course there are exceptions. U want to know what u are starting with so if u want to change anything u can understand the result.
Minimum base bevel for twins should be 1 degree.
All-mtn and pipe are similar u need some grip on the hardpack. If u go to 2 degrees on the side edge u'll get more grip on ice. A normal de-tune is tip and tail 4-6 inches with a fine dianond stone or a hard gummi.
Park/rails and also riding all -mtn/pipe is a tuning problem because for rails when u de-tune underfoot or bang- em up on rails u'll slide instead of carving down trails back to the lift. Bangin em up on rails leaves burrs, bumps and inconsistencies on the edge and they catch. U may even do some damage to the sidewall & core. So u have to use a stone and smooth the edge back down.
So for a more slippery ski for park some guys go more like 1.5 degrees or 2 for BASE bevel. u r at ur own risk because u bring the angle back up without a full deep base grind.
x games last yr they were tuning and waxing behind the scenes (made it on TV) and the pros even have their own techs - and their secrets.