Most Drills are tough to explain with enough clarity in a post like this for you to benefit. You need to be there and see it demonstrated and feel the sensations. One drill though that is fairly easy to explain verbally is what the previous person mentioned about Niclaus hitting balls with his feet on the ground, similar to the drill I described Michelle doing.
In this case, right foot staying glued to the ground until just after impact. Kenny Perry does this better than anyone. Caveats: do it with a half swing first until you master the move, then 3/4 backswing.And - if you lack flexibility, it is impossible to do without totally freezing out your pivot motion and making an all arms swing - which of course is the kiss of death
As for thoughts, I dont believe in ever using "swing thoughts" when swinging at normal swing speeds especially with the intention of hitting a golf ball solid and to a target. Thinking works as preperation before the shot though, in that case, just the concept I talked about inm the above posts that you need to "get it" that you hit the ball in the middle of a massive weight transfer, and that means trusting your innate athletic ability to make that kind of fast, dynamcic and "out of control" feeling (from an emotional and "common sense" standpoint) kind of move. Most golfers are terribly "ball bound" and "impact bound" and we have drills for those, a whole one day golf school in fact. The other concept kind of training that helps a lot of folks is understanding that the lower body pivot is never a conscious direct power source, ie let go of any notion of "driving your legs", "pusing off the right foot", "driving the right knee toward the ball", or "spinning the hips" for power. There are of course some tour pros who do some of things, but they get away with it due to superior athtletic ability and thousands of swings so they have grooved the compensations for both timing and balance issues. Most do not, even if they "think" they do, or they do it in a very gentle and subtle way. The whole "feel versus fact" syndrome. THe really good ballstrikers today who use the modern, compact, rotary style swing with few moving parts do none of these things, especially those who have worked with Leadbetter. Tongzilla described the sequencing above rather brilliantly, I think. What you believe to be true (subconscious mind - not concsious mind) as per your power sources becomes manifest in your body motion, and applying power with your legs especially is a really destructive idea to good balance, mechanics and timing.