Move as a chain - first guy is the anchor, the team files past (10 meter intervals and stop) and when the last guy has reached his spot (10 meters in front of the last man in the chain) the first guy can release his point and move to the front starting the whole process over again.

Spamming frags is both a waste of resources and holds your team back. Wait to hear an enemy before tossing a pineapple. They react to sound...a frag draws the close range bots like flies. Why warn the enemy you are coming?

Spamming smoke not only annoys but hinders your team. Smoke is to be used like Flash - you throw it at the feet of the enemy to blind him and mask your moving forward.
Using it as a duck blind is an exploit and cheap similar to killing all but one person to avoid a counter attack.

Interlocking angles of fire. As mentioned elsewhere regarding ADD. Pick a door and stick with it until you hear the other entry is open.

If we are in a single file corridor and you push past me, do not complain when you get shot from behind or kicked from the server.

Stick to your assignment - door whatever - stop running towards every sound you hear...like a bot.

Crouch if you cross in front of other players, especially the SAW.

If someone lays a frag on the cache, let them finish laying the second - stealing the taking of an objective is really poor form.

Before you go to pick up that shiny RPG or Resupply - make a 5 count. Someone always pops in unexpected to ruin your day.

If you are trying to draw the enemy, don't stand next to other people. You bring fire on people who do not expect it.

When playing HUNT, use a suppressor or take a route the rest of the team is not taking. YOU will draw fire your team doesn't want or need. Using a unsuppressed SAW in HUNT is facepalm time.

Incendiaries and Molotov's are for blocking ingress when two people have to defend multiple openings. They are not for kills.
When you toss them indiscriminately they block OUR routes. You trap us in small rooms etc. The Bots will walk through them.

Spread out - please do not back into me or push me when I was covering a corner before you got there.

Leave room for the point man to back the f&ck up. If they are on stairs etc and you bunch up behind them, they are dead, having no place to go.
And if a grenade or RPG comes - we are ALL dead.

If you walk into a server known for its default of BRUTAL difficulty, please do not start votes to change it to easy. There is a reason we were there playing before you joined.

Talk can cure most situations. A brutal opening? Everyone getting killed at spawn?
"Everyone frag and move forward..." Voila - we took Alpha.
Talk it out.

If all you add to the comms is, "OMG, that was cool." Mute your mic.

If you have less than a couple hundred hours in game, do not refer to others as noobs.

The option to restart a round by vote is for the occasion when everyone is dead except for one person who is AFK. Or if a map is bugged and you get stuck. Using it when someone is still alive and playing is the epitome of selfish.

Amendments:
(Thanks to SeriousCat & Zahadoom)

Slow Down, take a breath and look again before you move.

• Completing objectives without eliminating all enemies, since this triggers a counterattack or a new spawn of enemies and the stragglers from the original objective kill everyone from behind.

• People stacking up against an entry point, only to be taken out by a single RPG.

• Minimum spacing should be 3m and usually around 8m. Any closer you're asking for an RPG.

• Use the LMG to set up killing fields in lanes—it's not an AR with extra bullets. Using it as such is just wasting that class, preventing other, better players from performing that role in the team.

Flashlights and lasers call bots like a moth to a flame. Use them but turn them off when you don't need them. Flashlights have the added issue of blinding the rest of your team.

How an Insurgency Squad Operates

Positions:

Point can be Recon or Support.
Support is the tank; they get the front in most situations. Recon is "supposed" to issue the orders & scout the bad guys but since we all know what we are to accomplish and that there is little way for the Recon to assess the tactical situation, so Recon is Support's number Two and covers their back.
You want maximum fire power at the forefront.

Demo blows the cache, that is their only real function - so let them have that one.

- Rifleman is a general soldier. He can be the number two for the Demo person or the Sniper or any other position for that matter. His charge is to keep the Demo/Sniper person alive.
- Specialist can almost duplicate the Demo position.
- Designated Marksman can be Number Two for any other position.
- Sniper sits in the back on the large maps such as Sinjar and protects the rest of the squad. On the very small CQB maps, the Sniper gets the windows. No one else, just the Sniper. His number Two protects the sniper by watching stairs or other ways of ingress.

General Maneuvering:

A Squad is broken down into two person groups.

The Number One and the Number Two. One is in front and facing one direction while the Two is at least 10 meters behind facing the other direction. Who faces left and who faces right is to be determined by the duo. Any time they encounter two or more ingress, they cover their assigned direction and stick to it until dead - at which point they notify their duo.

ADD is the scourge of Insurgency. It causes people to TK as people run back and forth in front of streams of fire.
My eyes dart around, my weapon...not so much. ADD can kill you. If the room has two doors and there are two team mates alive - pick a door and stay there until dead or relieved. Running back and forth between the doors will get you unintentionally but rightfully TKed
Lack of coherent communication is also a bad thing.

Telling people to watch "left" or "right" causes confusion. A clockface should be used instead as Nine O'Clock can only be in one direction from where you face.
"Tango at 3" is succinct and cannot be misread.

As a player you must be all invested - if you are checking your phone or texting, we lose.