What a la la la la sack of hackneyed platitutes .... communication ... key ... crap.
#1 most important move is stacking attack. You've got to be able to count and follow. You don't have to do much else.
#2 most important move is concentrated take-out. It's a +3 bonus that can't be broken. It's most valuable on medium to small maps. Again, count and follow.
#3 most important move is the 1-2(-3-4) punch. I don't care to elaborate on this one, but here's a hint... it's for big maps. You have to count.
#4 most important move is the back out. It's like the stacking attack, but you are setting up you teammate to attack you... usually.
#5 most important move is showing multiple targets. This is how you get around the opponents attempts at #1. It sort of works also for #4... sometimes.
And probably the most controversial move, one I like but not too many other people seem to get is the "clear the deck" move. Used in desperate situations when #4 just won't get you there fast enough.
Learn to recognize these tactics, and the conditions that you need to use them in, and you'll do fine even if you are speaking greek and your teammate is speaking latin (does anyone still speak latin... ??).