Visual learning

In order to understand the best way to execute any skill or technique we have to look exactly to what the pros are doing. There are certain things that all the pros do differently. Other things that there is a certain tendency in the pros game. And then we have the commonalities that all the pro players do, maybe with one or two exceptions.
Understanding those common elements of technique in all the pros gives us the knowledge and power to improve our own game.
When I'm analyzing my own or someone's strokes I isolate one certain element of the skill and compare it with all the pros. What is it exactly that I'm doing that all the pros aren't doing? That way my analysis will be as objective as possible. For instance I will not waste my time to explain why I prefer Federer's forehand grip to Nadal's or vice-versa. I'm more interested in knowing what are their common elements in their forehands.