Put mine on the front left in a position where my left thumb is in perfect position to operate it. Very intuitive to use in this orientation.
By the way, bo tach Tactical has the new TLR-1s (strobe) for $108. It is 300 lumen compared to the original TLR-1 having 160 lumen (or there abouts). Very nice light for the money. Love my original, the new one is even better.