Recreational golfers who constantly struggle to fix their swing problems would do well to fix their posture first. Rounding the back, flexing the knees too much and tucking the head down to see the ball are common setup faults that can lead to a poor swing. If your posture isn't right, you'll be forced to swing with mostly your arms and hands, creating very little shoulder turn.
If this sounds like you, here's a drill you can try within the confines of your own home. Stand in front of a full-length mirror and bend from your hip socket so that your upper body tilts forward approximately 45 degrees. Notice that your head is in line with your spine and isn't tucked downward. Next, release your knees slightly. A problem most golfers have is too much knee flex and not enough bend from the hips. Finally, let gravity drop your arms and club to the ground (they'll naturally hang straight down if you've achieved the correct posture). This improved position will enable you to make a more complete shoulder turn without a lot of arm and hand action.
PGA professional Heath Talbot is the director of instruction of the Raptor Bay Golf Academy in Bonita Springs, Fla., in the winter and is a teaching professional at Eagle Springs Golf Club in the Vail Valley of Colorado in the summer.