1) There is nothing ever worth fighting for except Democrat policies: If you're going to fight for something, make sure you're fighting your own base to help the Democrats achieve some policy goal that makes Tea Partiers want to stab themselves in their eyes. This makes you appear reasonable to the mainstream media and the howls of outrage from your base make it more likely that the New York Times will say nice things about you.
2) You must systematically destroy any person, place, or thing that excites conservatives: Nothing good ever comes from conservatives getting excited; so make sure to target anything and anyone that gets them fired up. If it's a person like Ted Cruz or Sarah Palin, trash him or her publicly or have your aides leak stories to the press if you're not brave enough to go that far. If it's a strategy, put it down and undercut it at every opportunity. If it's a group like the Senate Conservatives Fund or Freedomworks, scorn it and complain that it's bad for the Republican Party.
3) You're a winner just by virtue of being an establishment Republican: When Tea Partiers rally behind a candidate who loses, it's because those guys don't know what they're doing. When establishment Republicans rally behind a candidate who loses, then they obviously selected the best candidate and no other candidate could have won. Establishment Republicans have a great formula: Win races, do nothing with that power that will make the media mad at you, which leads to more victories, which leads to doing nothing with that power that will make the media mad at you and so on and so on until the GOP totally dominates. Sure, that strategy may have lost the GOP the last two presidential elections and has produced only 45 senators so far, but it should start working any time now.
4) Trash conservatives, but hold your fire against Democrats: There's a reason that both John McCain and Mitt Romney fought harder against their Republican primary opponents than they did against Barack Obama. The liberal media applauds you for saying mean things about conservative Republicans, but they hate it when you go after Democrats. If it comes right down to it, it's better to go down to an honorable defeat than to win and have the media angry at you because you won a bruising race against a Democrat.