Here is an idea that I've read about but have not tried...Break up your round in groups of three holes. In other words, focus on three holes then take a mental break and review what you did. Then begin with the next three holes and focus on just those three holes. Doing this will help you concentrate (focus) for a shorter period of time. Sometimes when I play my mind begins to wander around hole 14 or 15 maybe if I think in groups of three that will get me through 18 holes easier. Just a thought. It seems reasonable to me that you might become more consistent if you break the course into 6 groups of three holes.