Training your putting stroke

The simplest way to move the putter in the moments before, during and after impact is directly along your intended starting line. 

Quite simply, the stronger the arc of your stroke, the more precise you need to be with your set-up as if the ball is slightly too far forward or back in your stance, the arc stroke will make it very difficult to consistently start your putts down the intended line. This simple drill involving a putting alignment mirror and some tee pegs is very effective.

Using the tees as a gate, you can ensure that at impact your putter head is travelling in the right direction. 

By missing the tees both back and through you will train yourself to start putts on the intended line. Pulling it outside the line at any point may lead to inconsistency, so make sure you miss the tees both back and through.