In my opinion posture is one of the most important things to get right and I find myself working with students on this every day. Your posture either enables you to make a fundamentally sound swing or forces you to make a series of corrections throughout the swing. Good posture makes it much more likely you will swing on plane and make proper hip and torso rotation allowing for maximum power.
Everyone has heard the basics on posture a thousand times… have a slight flex in the knees, bend from the hips not the waist, have your weight balanced between the right and left foot, and let your arms hang freely from your shoulders. But here are a few specifics to help you create optimal posture for making a fundamentally sound and powerful swing.
First you want to learn how to get into a proper pelvis position with a neutral spine. This means your hips will be set at an angle that will allow you to create a fairly straight spine (approximately 20 degrees). Use the Pelvic Tilt find Neutral Drill to help with neutral pelvis position. Place a club from your tailbone to upper back and make sure you have no more that a finger width between club and lower back.
Next, to ensure you don’t slouch or round your upper back, use the Posture Stick Drill to straighten out the upper spine and help with neutral posture. For most people this involves pulling the chin into the neck (as if giving yourself a double chin).
Once you are able to feel this, use the Toes to Knees Drill to establish the right amount of knee flex and upper body bend. Next you will want to engage your core and balance your weight in the middle of your feet.
There is no better drill than the Half Foam Roller Posture Drill to learn proper balance as well as core engagement at address. As a final check, record your set up position and draw a line straight up from the balls of your feet. You will want to see the kneecaps touching the left side of the line, elbows touching the right side of the line and for the line to extend through the back edge of the shoulders (reverse of left handed).