What sort of generally good practices can I adopt when I participate in team games, and what are the types of faux pas I could keep in mind to avoid? I've only done two team games so far. In the first one I had my commander to myself and to a large extent we used infrastructure and forces on a you-build-it-you-command-it basis. No arguments but also little coordination in general. In the second one I assumed I would at least keep my commander to myself and gave him a hotkey to help make sure I'd keep an eye on him only to have my orders and queues countermanded on a regular basis, with the result that I lost interest in watching over him and lost him early on in what appears to have been a solitary expansionist venture by one of the other players. Various orders I made to put some bot armies on assaults, raids, or micromanaged defensive maneuvers against enemy formations were loudly objected to and/or countermanded. This despite me having considered my intervention in the management some of the forces in play to be worth the two resulting enemy commander deaths managed before retreat and reinforcements could limit the damage to only some of the p-gens caught in the commander detonations. I usually don't even have a clue whose orders I might be countermanding or who might be countermanding mine. Halp?
Team games with people you don't know/don't have experience play with really doesn't work well. The "you built it you command it" approach is the most common as far as I can tell.
When I'm playing with random people I typically build my base away from my teammates and handle my own things. However, I will give orders to idle units/fabbers/factories that my teammates might have, and if an ally is tanking the economy building stupid things, I'll attempt to mitigate the damage by trying to pull some of the build power off. Some people will throw a fit if you touch their stuff though, and will delete all the commanders in retaliation. I haven't had it happen to me, but I have won a few games thanks to tantrums.
Ideally find people who are willing to share everything given the right situation, and then generally stick to managing your own stuff until necessary. For example, taking two comms to fend off a comm rush while the other player manages Eco, other forces, or repairs etc. I don't think you can be an effective team if you aren't wiling to cooperate like this.
Bad. C selects all commanders. Double tap to cycle commanders is good though. Means you can check your commanders for safety quickly Err.... absolutely abuse chat. You have to communicate a LOT. More communication you have, the better. Start with 'I am the Raptor commander', and go from there. Explaining 'why' is often the best strategy, as often people are better about you doing stupid stuff if you can explain in a chat message why it is not stupid. If someone's commander is idle early game, they are fair game. If your opponent complains about your display of cooperation with them, you have a really bad teammate, I'm sorry.