[golfguru]

Pre-shot - planning, visualising, collecting your required action to get the job done.
Execution - allowing your skills to execute the pre- planned action
Post- shot - enjoying the result and or comparing the plan to the resultant effort.

If you are over thinking, you are likely to choke your actions via being too controlling of skills you really own to a non-concious level.

Over concentration for an entire round is energy sapping. So save that energy for focusing on what is required in 2 minute bursts - walking to your ball, assessing the situ, working out the shot, making the shot and assessing the result....then back to the bag, chat, walk, drive up to the next mini focus session.

We can all tie a shoe lace and talk at the same time. We can do the same with our golf swings. Plan, execute. Yoda says fill up your cup with the good stuff....then you have to execute without being mind cluttered.

Focus- knowing what to focus upon - is a result
Concentration - knowing how to focus on the important things going on - is a process.