Practice Swings.

[Losttheplot]

I do use a practise swing but it's only one or two to feel the club path on the take back, ball strike and follow through. This is done behind the ball so I can walk towards the ball and I'm looking at the target in a straight line. I can then align myself, get set up then strike. All in all probably 10-15 secs from complete start to finish.

The time for 'practising' your swing is on the range.
When on the course I think you should play naturally and not think to technically. Just trust your swing and feel for it.

The short game is similar but practise next to the ball, two or three practise swings feeling for the weight of the club, power needed in the shot and visualising the chip or putt. This again is only 10 secs or so.

 

[Warren]

I'll take a practice swing to loosen up before the shot, but mainly it's my pre shot routine to get in the zone before my shot.