A bit of a whine. . .

If you aren't using the enter key to talk to your teammates, you will lose.  A lot.  It is the single most common correlative action with losing.  I played a very frustrating game where it was impossible to coordinate anything.  I was calling out targets, stating when I was OOM or needed to retreat.  My teammates didn't type a thing, except that after our citadel fell one of them typed that I complained all game long.

Great.

So please, here are the things you should be typing during the course of play:

1.  'b' or 'B' means 'back up.'  If you need to leave the fight our you realize you're going to be at a disadvantage, type this.  It warns your teammates to retreat.  If you do not, you risk leaving someone behind to be ganked.
2.  'OOM' means out of mana.  Type this when you do not have enough mana to fight.  This is most important for mana dependent characters.  If your Sedna says 'oom' do not expect a heal.  If your TB says 'oom' expect him to be leaving for a crystal.  Your teammates will evaluate their situation differently if the QoT or Oak says OOM because they know a shield is not coming to save them.
3.  'In town' or 'shop'.  Type this when you're pulling off the line for shopping.  Your teammates know you're not around and the numbers are not in their favor.
4.  '(number) left' or '(number) right'.  Type this to indicate how many opponents are currently on that side.  If it's a 3v3 game and someone types '3 left' you know there is a mismatch.  It can be either a problem or disadvantage, but it's important information nonetheless.
5.  'Any DG name'  Type this to indicate which DG your teammates should attack.  This is probably the most important information shared in a game.  In a 2v2 fight, if two DGs are attacking one target and the other two are attacking separate targets, the uncoordinated team will lose EVERY TIME.  Honestly, this is what triggered this post.  In the game that flustered me so badly above, at no time could we coordinate an attack.  And, being the Sedna on our team, I was always the one double (or triple) teamed.  Eventually, I just had to run from all encounters and, frankly, I just gave up.
6. 'to me'.  Type this if you want a player to come towards you.  I use this a lot to tell players to come to me for a heal.  Often, a player will retreat out of range of my healing and if they turn around they can survive.

Honestly, just using that much typing is the difference between basic play and the next step up.  Nothing requires more than a few characters and you should be able to type them quickly.