This is my pre shot routine, its got to be so natural that it comes naturally to you. You can't think about it when on the course. With people around, the nerves will get to you and the possibility of a mulligan is high. So practice this at the range before heading down to the course.
1) Face my Clubface to my Target Line (Target Line is an imaginary line drawn from the golf ball to the target, say the flag)
2) Ensure the Golf Ball is in front of my left heel
3) Stand straight, Spine Angled, hand relaxed and pointing down. I should be able to see the index and middle finger knuckles with my left eye at this point. Wrist should not be too cocked or too straight. The wrist angle must be just nice. Biceps on both arms are squeezing my chest. This allows a constant, if there is no pressure between my bicep and chest, during the takeaway, the hands will "flail" around, which leads to inconsistency. Hence the pressure between the bicep and chest is important.
4) Ease my knees down, and spine a little, until my clubface reaches the ball.
5) Count 1, move hands, forearms straight.
6) Count 2, Turn shoulders, wrists cock naturally, full shoulder turn, left shoulder passes right knee, right elbow points down when the club is at the top position.
7) Count 3, shift weight left and allow arms to fall back down.
8) Mid way down, right elbow must be tucked into right ribcage, to ensure an in-to-out swing.
9) During Impact, Head is behind the ball, after hitting the ball, allow the spine angle to remain angled as you swing your arms up. Don't straighten the spine too soon. If you stood far enough from the ball, you will have enough space to swing through with your body and not the hands.
10) End with a nice finishing pose, Right Heel off the ground.
Try it, a pre shot routine helps your ball go a long way :)