I would start with some kind of spring upgrade, either the heavier Polaris spring or go with an aftermarket set like Raptors. The Raptor springs are a nice upgrade that don't break the bank.
Once that's done or if you decide on staying stock, then move to adjusting.
Start with the rear track shock and use the manual for getting a "starting point". What ever the manual says to set it for with your weight, just start there. Once you get the rear track shock set, ride it and don't be afraid to adjust it. Just remember what your starting point is or "zero" point, that way you can always go back.
This first adjustment on the rear track shock comes down to your riding style. Stiffer for the guys who jump and do more drops and on the loose side for the powder rider, or .......a combination somewhere in between for most guys. I like to run my RTS as loose as possible for the best deep powder performance. My RTS is set so that I probably bottom out a couple times a day. This way you know you are "using" the shock to it's capabilities. Some guys have the notion to just dial everything tight and run it like a po go stick. This is just handicapping your shocks performance. Again, mine is set so it bottoms once and while on the bigger stuff, other wise it's just working.
Once the rear track shock is set to your liking, then move onto the front track shock (FTS). This adjustment is truly rider specific as to what "you" like. More spring tension will make the front of the sled feel lighter or as some would say "flickable". With more spring pre-load / shorter spring the front will pop up more but, you will also notice the rear starting to trench as this increases.
Less spring pre-load on the FTS will make the front of the sled feel more planted and less pop.
The key here is finding what works for "you" and that balance between front end pop and the rear of the skid getting on top of the snow quick.
Anyways, hope that helps a little.
