1) Take out the "big boys": If you have and Epic Duel deck and you're ready to duel than that can save you, removing Obi and Luke should be enough to keep you alive.
2) Magic bullet cards: Wounded Wookie can be used to get rid of the extra destinies, Your Powers Are Weak... can stop the Jedi Presence, Imperial Barrier can keep you alive for a turn, N'gok works like Barrier but for their entire squad. Imperial Supply, played correctly may save you from the wrath of Draw Their Fire, allowing you to play ghhhhk. Perimeter Patrol, this will all but destroy a beatdown deck, by removing it's ability to "jump" you. Don't forget about Sense and Alter, which can cancel most of your opponents cards.
3) Stay away:Simply play in space, or stick to safe sites with a Hutt Smooch or Ephant Mon.
4) Be prepared: If you have enough power to withstand a mains beatdown at a site, then don't worry, but this is unlikely.
5) Break their combo: Use cards like Scanning Crew, Monnok (used) and Uncertain is the Future and Miyom Onith to manipulate their hand.
Any one of these strategies, followed correctly, can save you, however if you ignore the advice and say I have a little of all and will be ok, don't be surprised when Vader and company stay the night at the smackdown hotel, along with the rest of your deck. Id.