Now this may be just because I am low ranked at the moment, but some things I am seeing are really starting to grind my gears.
So here are some quick tips:
1. DO NOT bring a stock ship. I have come across numerous matches with teammates who brought stock Clevelands, New Mexicos you name it. It is more detrimental than you think. Not only do you have lower HP, but your firepower, AA, and Maneuverability lack significantly.
2. Premium Consumables. That shorter cooldown on damage control helps tremendously, as does the other consumables like the spotter plane, or hydro search. They are relatively cheap so don't worry about your wallet, just use them(Disclaimer: DC is the premium consumable you always want to use. The other one's while extremely helpful are not as important as DC)!
3. Flags and Camo. While not as important as a non-stock ship, flags and camo give your ships boosts in firepower, survivability, and credit income that make you an even great asset to the team. Heck, the rewards you get in the rank season are flags and camos, so there is even less of an excuse!
4. Communication. Communication is key! Let people know what you are doing, whether it be where you are scouting, laying smoke, or capping. The more in tune you are with your team the greater chance you will come out on top. Support your allied ships. Move as a team. Focus targets.
5. AP vs HE. Learn when to use the correct ammo type. Angled ship coming towards or away? HE. Broadside cruiser? AP. Now of course it isn't all cut and dry, but doing this can reward you with tasty citadels, and will net you a few kills as well.
6. Patience. In Ranked battles every ship matters. That may sound cliche but it's true. More so than ranked, one ship means a lot. The team that loses a ship early on more often than not has to fight an uphill battle that becomes almost unwinnable. Now that is not to say you should give up if this happens. However, think through your decisions before you make them, they mean a lot more in the scope of the match than in Randoms where one lost ship is more or less irrelevant, at least to the point of making a comeback.
7. Lastly enjoy yourself. Ranked battles can get people's knickers in a twist, and the last thing you want to do is stress out about every game you play. If you lose 2 or 3 in a row, stop playing and take a break. The amount of tilt one can have in this position is greater than you could imagine.
These tips may seem trivial and logical, but there are people out there that don't think twice about it, and at the end of the day it would not only improve their game, but their team's game as well.
P.S. Sorry for any grammar mistakes, at 1:40 am I'm not too keen on remembering High School English.