Short Version:
Keep your left arm straight taking the club back as you coil around your right leg fully hinging your wrists. Uncoil turning to your left side (the uncoiling will help propel you to your left side) with your arms following your shoulders and your wrists unhinging automatically (it's not an arms swing - it's a body swing). You end up facing the target with almost all your weight on your left side.
Long Version:
Keep your left arm reasonably straight (as much as possible for your level of flexibility - the important thing is that the left arm is straight at impact) while coiling around your right leg fully hinging your wrists with your left shoulder getting near your chin. You uncoil turning forward with your arms moving at the same speed as your shoulders and your wrists unhinging automatically - you complete the swing with your belly button facing the target with 90 percent of your weight on the left leg. You will see the ball and your arms will want to hit it. Don't do it. Make the swing through the ball and make sure your arms don't swing at the ball - the golf swing is a body swing - not an arms swing. Do all this with a smooth tempo while staying on plane throughout the swing - no popping your head up.
1. Button and treads - swing so when you finish your belly button is facing the target and a person behind you can see the treads on your right shoe.
2. Always accelerate through the ball - hit through the ball - not at the ball. Even on the shortest shots accelerate through - just don't take the club back very far (if you decelerate you'll hit behind the ball). Play the ball in the middle of your stance - slightly forward with longer clubs.
3. Keep your left arm straight as much as possible making a nice wide swing. (If your left arm is straight you can feel it moving with your body.) I think of my arms following my shoulders as my shoulders turn. (The left arm needs to be straight at impact - professionals with great flexibility can keep their left arm straight throughout the swing but the rest of us can't - don't worry about it.)
4. Tension is bad since it restricts the body. There are golf shots that require some tension in the arms (an example is pitching when you need to keep your wrists firm) but as a general rule tension in the arms is harmful to the golf swing.
5. Keep your head fairly still and try to watch the club hit the ball - don't slide back but coil so your back tends to face the target. Coiling is huge. (It's likely that if you're not coiling you're swaying back with the result that you will not be able to get to your left side.) Uncoiling will help you move to your left side - you need to get there.
6. Your hands and arms go along for the ride - once you have taken the club back think only about turning to your left side - your hands and arms will follow. Stay on plane. (Golfers are human beings susceptible to stress. Your body will tense up under stress and not move. When facing a stressful shot relax and turn to your left side - if you don't, you'll hit behind the ball.)
7. Keep your head down. Aim in front of the ball - if you aim at the ball you may end up hitting behind the ball because of the lag of the club. You need to hit the ball before you hit the ground. Your wrists need to fully hinge to get power (this will tend to happen automatically at the top of your backswing if your wrists are loose and your backswing is complete) - you never have to think about unhinging because the wrists will unhinge automatically and provide the whipping action that generates clubhead speed.
8. Hit from in to out as though there's a ball just outside your ball and you don't want to hit it. Keep your right side tucked so you can almost feel your right elbow touching your right side (if your arms get too far away from your body you will lose power and control). For me keeping the right side tight to my body is extremely important because it prevents me from making an arms swing and gives me control over my shot.
9. In a bunker it's natural to look up too quickly - just keep your head down. Don't slide back - if you slide back you'll hit too far behind the ball. Hit at a spot a couple of inches behind the ball - don't make contact with the ball - swing into the sand. Finish the swing - this is really important. I use my 64 degree wedge - you do need a lofted club. I swing hard with my body - the sand needs to move. I use my normal swing. (I'm just trying to get the ball on the green. I would need a better technique to get the ball close to the hole.)
10. When using the driver tee up the ball near your front foot and hit through the tee (the club will be coming up). Let about 50% of the ball be above the driver when the driver is grounded. I think about a low and wide backswing and sweeping the club through the tee when I rotate my body forward not using my arms. My arms want to take over but if they do they will move faster than my shoulders are moving and I will hit the ball to the left.
11. Putt with your shoulders stroking down and through making contact with the center of the putter. Take the putter straight back and straight through. Don't bunt at the ball - putt smoothly through the ball giving it a nice roll. The speed of the putter going back should be the speed of the putter going forward - I try to get this nice even tempo by counting to myself. A light grip is important for putting. Take the putter back more for longer putts.
12. When chipping make sure to stroke down on the ball. To make sure this happens grip the club with your left hand so you can see four knuckles. Play the ball back in your stance. Chip the ball onto the front of the green and let it run to the hole. Figure out what clubs should be used for different distances. A chip with a wedge will not run as far as a chip with a 7 iron. Chipping is like putting. The body stays quiet and the wrists stay firm. Be sure to accelerate. Keep your weight on your left side. As in putting count to yourself for a good tempo.
13. When pitching keep the wrists firm. The more you follow through, the higher the ball will go. Be sure to hit down and ahead of the ball with the club moving with the turn of your body - I think of taking a divot. Play the ball back in your stance. Pitch with the right club for the situation - if the ball needs to carry a good distance use a less lofted club - remember to accelerate at impact (this is the shot along with a putt and a chip that is most susceptible to deceleration). Pitching requires some coiling of the body.
14. Downhill lie - keep your weight on your left foot and lower your left shoulder. Uphill lie - keep your weight on your right foot and lower your right shoulder.
15. Have someone watch you swing. You may think your swing is OK but what you think is often not the reality. You need confirmation either from the result of the swing or from an educated observer.