Dan McLaughlin, writing in his blog Baseball Crank, lists 73 rules for running for President on the GOP side - they are really good. He has done some serious thinking about what causes Republican candidates to lose, and has written rules to avoid the worst potholes.
When the RNC holds training for candidates, I hope they use these rules as a major part of the structure. They are written for presidential candidates, but mostly would apply to a House or Senate candidate as well.