Layering tips from the locals:
There are so many great options available when it comes to layering for maximum comfort on the slopes in the back country or on the trails...

First Layer...
Next to skin layers should be thin and snug fitting.  One can choose a polyester synthetic or a natural merino wool product.  The synthetics tend to wick or move moisture a bit faster but the merino remains warm even when damp and retains no body odor unlike the synthetics.  Generally a snug fit is important for maximum moisture transfer to the outer layers which keeps your skin dryer and therefore warmer.

Mid Layer...
In cold weather it is usually important to add a mid layer. That layer could be lite weight down; fleece or merino.  This mid layer helps in trapping air and body heat to keep you warm in winter conditions.

Outer Layer...
The outer layer is important in all seasons when you have wind, rain or snow. Even in summer weather you need a rain shell to keep dry in a thunder storm.  Hard (nylon usually) shells are best for rain, wet snow and lift service skiing.  More breathable “soft shells” made of a variety of fibers are excellent for more aerobic sports like x-c skiing, back country skiing and cycling. Usually one needs a small “quiver” of shells to satisfy either the sport or the conditions. Outer shells are also equipped with a multitude of special features that make a big difference in performance.  Pit zips, hoods, powder skirts, adjustable cuffs and drawstrings all aid in the adjustment of fit and comfort of the garment. 

Layer Top and Bottom... Remember layering the bottom half of your body is just as important as the top/trunk half.  Generally you can go with a little lighter configuration on the legs unless you are in very high alpine conditions or sitting in a kayak with legs near cold water and not moving too much.  The same fabrics and feature options are available in pants (minus the hood of course) and the same general rules apply depending on activity.

What’s new in fabric and construction? 
These are always changing and evolving, but recent developments include “tiny tape” on waterproof shell seams; seamless construction where the garment is actually welded together and not sewn; highly water repellant soft shell fabrics and stretch has been added everywhere.  We prefer a mechanical stretch (pigtail fiber) in outer shells  as anything with lycra does not dry as fast, weighs more and the stretch wears out sooner.  Even merino wool garments have made a comeback with waterproof zippers and extra DWR (durable water repellant) treatments added to the outside of the garment.