fore & aft centering breakthrough!OK, you are asking about bumps, and you're an advanced skier, wanting to be (continuously) more centered.
Here is some imagery that will break you through; use if first on groomed terrain, then adapt it to the fall line bumps. Believe it or not, this solid movement pattern will carry over quite literally into bumps, as well as other varied terrain and conditions!
If this sounds too elementary, my apologies, but...
Stand at the top of a medium-steep groomer. Before you take off, become conscious of this "triangle": your heel, your ball of foot, and your shin in light contact with the boot. Now, slide into the fall line, and link some medium radius turns, being very conscious to maintain the triangle, with consistent, even pressure on each of the three points. Don't "lever" the triangle throughout phases of your turns. Be especially careful about maintaining the presence of shin to boot, neither letting the shin come off the tongue, nor mashing forward against it. With your modern, shaped skis, ankle/knee angulation is the only active movement of lower legs necessary. The triangle has your feet & lower legs somewhat static compared to the feeling you may be used to, at least in a fore & aft plane.
If your shins gap from the boot tongues, particularly at the end of the turn, think of sucking your feet back under your body during that part of the turn, holding them back as you roll into the next edge set with pure lateral movement.
It may feel that you are "doing less" than you are used to in your current movement pattern, and therein lies the breakthrough! Now, GRADUALLY take this restrained stance into terrain and bumps. Resist the temptation to go back to excessive active movement of your feet! You will find your bump lines better, with the abilty to plan and react much earlier.
Another simple piece of imagery, as an alternate to the "static triangle" is to visualize the entire your weight settled upon the entire soles of BOTH FEET, from heel to toes, ALL THE TIME, THROUGHOUT THE TURN. This, too will accomplish two-footed, centered stance and better skiing on all terrain and conditions. What we are getting at is breaking the habitual active movement of the feet, which is superflous and destructive to strong, balanced & centered skiing!
OK, just one more: picture both skis in predetermined tracks as if engaged on the rails of a roller coaster. They must both remain in/on the snow. There is no lifting or pivoting allows, as your skis are merely casters attached to the train rails. Therefore, the only body movements allowed are those adjustments which keep your body in dynamic balance while the skis travel along your intended arcs.
All of these imagery techniques are designed to point to the same goal; constant two footed, centered stance where both skis STEER all the time.
Trust me, whether you want faster NASTAR times, better bump lines, or less fatigue (or all of these). You don't need 10 techniques, just one consistent movement pattern that carries you well into your most radical mountain situations with strength & elegance.