As Jed said, dynamic snowboarding does not refer to any specific way of riding; there are lots of different ways to get dynamic. I think of dynamic principles as ideas which can be added to your solid basic turns, not a different style of riding (though it will define your style). It's actually a really complex (and fun) subject that is beyond the scope of a simple forum post or youtube video. If you can afford a lesson, get one.
Usually the first dynamic principle I introduce is weighting and unweighting the board through the turns. Typically you'll want to unweight the board for the edge change and actively weight it through the turn for extra turning power. There are different methods of accomplishing this. Either you can unweight by rising up for the edge transition and dropping your weight down while turning (cross over) or unweight by quickly flexing the legs and then slowly extending through the turn for extra power (cross under).
You can also get dynamic with active fore and aft movements. We all know that we have to weight the front foot to get a speedy turn initiation. As you start your new turn, exaggerate this weighting of the front foot, but after the turn is established experiment with the idea of pushing the back foot toward the front foot so that you're actually a bit aft (heavy on the back foot) at the turn's completion -- just don't get so far back that you can't get forward in time to start your next turn. See if you can't bring your turns around faster with this technique.
Timing is extremely important for making these movements effective, so feel the rhythm of your turns and find where these movements fit in. Also, there are many other ways to get dynamic than just these, and they can be used in conjunction with each other, or in isolation.
Edit: Effective dynamic riding techniques can be performed in any normal, functional stance, forward or duck. If you always find yourself wanting to open your shoulders/hips and rarely/never ride fakie, you might just want to consider changing your binding angles to something that is more comfortable/better suits your style.
Last edited by stillz; 01-18-2014 at 08:35 PM.
Reason: Didn't address OP's question