Many components of the golf swing can be preset at the setup position. Here is a tip I use (and Greg Norman uses) that can help get the left arm and hands and club in a nice position at setup to help with a squarer clubface and a squarer setup in a balanced look.
We often hear the weight should be back for woods and forward for short irons- here's the key to a better weight distribution at setup to help your swing stay balanced
How we view things is important to how we step into the ball and align ourselves. 
We always are told to pay close attention to the target. Focus on it. Small target- Small miss is what they say if the shot is less than perfect. I totally agree. However sometimes the flag doesn't have to be your focus.
I guarantee every golfer has had a playing partner tell them- "You hit it right where you were aiming". There are two reasons why aim is over rated and you DON'T have to aim straight. Watch to learn why.
A proper grip is necessary to control the club- which is swinging at great speed out and away from us...And to control the clubface so we hit the ball and squarely and crisply as possible. Here is how my drill one takes care of the grip- for the better...