I would venture to say that I am one of the few who do not have much of a pre-shot routine. Traditionally I will stand behind the ball about 4-5 feet to eye my shot and angle at approach. I will hold my club straight up to get the line, take a step left and then walk up to the ball and hit. I do not take a practice swing (unless of course I am in a poor lie or up near the green chipping, anything with finesse really.) From there, I step up and let it fly.

Blake,

  I seem pretty similar to your style.  I tend to spend more time on chips, pitches and putts but full shots, I take a peek, find my line and hit the ball.  

Greg

I've always found this works a little better. When I play with a few of my common competitors I always notice they waste time taking 3-4 practice swings, which occasionally contribute to a lack of confidence should they take a fat swing, etc. 

I find more confidence in believing "I have this shot" type mentality, hence the step up and swing.

On full shots, I stand behind the ball, pick a line and a spot in front of the ball for alignment.  I walk up to it, take a 30-50% semi practice swing, sometimes my left shoulder pops on a full swing, but very rarely two swings in a row, so the slow swings usually eliminates this on the actual contact swing.  I do take a couple of practice swings when chipping / pitching.  I don't when putting, my wife watched me one day and said my first putt stroke always looked better than my actual one, so now I just step up and stroke the putt when I get my line. 

My pre-shot routine is pretty simple. I stand behind the ball to get my line, approach the ball, align the club face, take my stance, and swing, and I do it for every shot. I don't take practice swings, I don't waggle, and I never change it. The whole idea of having a pre-shot routine is that it is always consistent. It's one of the few things on the golf course you have the ability to keep consistent.

Think about it. Courses change, course conditions change, weather changes, your ball - during the course of play - changes (scuffs, dirt, grass, mud, etc.). I'd say a good 90% or more of the things pertaining to golf change. So why not take advantage of a good pre-shot routine to create some consistency in your round?