Well, studying the feet of some professional golfers during their downswings might just pay off. Look at golfers like Rory McIlroy, Kenny Perry, Ben Hogan, and Jason Dufner. As it turns out, some of the best ball strikers in history worked to keep the right foot planted for as long as possible during the downswing. In other words, the back foot may roll inward slightly towards the inside of the toes during impact, but the foot should only come up on the tip toes at the very end by being forced up by the finish. You should never TRY to come up on the toes through impact; if this is a habit you ingrained early, you'll be doing a good thing to try to reverse it. Why?
Set up like you're going to hit a ball and begin coming up on the toes of the right foot during the downswing (through impact). Notice what happens with the hips. They open up sooner. Keeping the right foot planted longer through impact keeps the hips from spinning open agressively too early and prevents the angle of the pelvis from improperly changing. The primary and secondary spine angles are retained during the turn-through.
It's important to couple this with the proper shoulder plane rotation. Done properly, the knees will finish very close together; otherwise, you will notice a larger gap between the knees at the finish.
MY RIGHT FOOT STAYS DOWN
This is more evident when I hit my irons, but I keep my right foot on the ground for a long time during the downswing. It helps my stability and lets me create more leverage to deliver a lot of energy into the ball. Plus, if you get up on the toes of your right foot too quickly, you can bet the club is not staying in front of you. Think about keeping your back heel grounded for as long as possible as you swing down. You'll be surprised how well you start striking the ball.
One of the parts of the swing I like to see is when a golfer has a right foot that is flat at impact or close to it. Granted, with longer clubs this is less necessary and more difficult to accomplish, but if you can get somewhat close then that's pretty good.
In the next sequence, it is clear to see that my right heel is still very low to the ground, but the entire foot has rolled up off the rope and in toward the left foot.
If you're a "hip spinner" as I discussed in the Hip Spinners video, doing this will create a sense of being "anchored" to the ground and provide a refreshing sense of stability at impact.
The right foot is actually a reaction to a good swing. If you stay down, the foot will SLOWLY rotate without coming up too quickly. The other option is the foot comes up and out too quickly and you will most likely hit a slice or block.