The latest update brought us some new 2 player vs 2 player modes . This one tip will step up your 2v2 game. When you select a card, hold your finger on the screen where you intend to drop it. It will not drop until you lift your finger but it will show a ghosted image of that card in that spot on your partner’s screen. 

This is amazingly helpful! If you plan to put a high value card on the field, show that to your partner so they can plan to put support troops down with it. You can do this trick while you’re still building up elixir for the card.

This is also extremely useful on defense. No more over spending on a counter when you and your partner both send arrows to take out the same swarm of goblins. If one of you signals your intent the other one can spend their elixir elsewhere.