Shooting and Fire-Modes:
The bare-bones of surviving in INS is being able to aim and shoot effectively. It is important to realise that in INS the weapons are depicted after their real world counterparts, complete with all the side effects, such as recoil and weapon sway. What this means is that you will not succeed by going around holding down your fire button, as your weapon will jerk around out of control and you will not be able to aim. Consequently, you will find your weapon will be much steadier and easier to aim if you are Crouched (Default 'C') or in the Prone position (Default 'Ctrl'). You will also present a smaller target to your enemies in these positions, making you harder to hit!
To improve your aiming even more, you are able to lift your weapon to your eyes and look down the Iron Sights (Default: 'Right Click'). Don't ever think this is a waste of time, as it will dramatically improve your aim, and you will find all competent players use their iron sights almost exclusively. The only times when it is not smart to aim with your iron sights is when you 'run into' an enemy an enemy that is only a few metres away- it is then a better idea to "shoot from the hip" (ie. not in iron sights mode), though this does take practice as it shoots where the weapon is pointing (not at the center of the screen).
To shoot effectively, I recommend getting used to using "semi-automatic" fire. You can access this by changing fire-modes (Default "F"), until you see a single bullet icon on the bottom right of your screen. Semi-automatic mode means that every time you click your mouse, you will fire a single shot. It is the most accurate firing mode available, but does take practice to get used to! This mode is best for long-range combat, but can still be used up close to devestating effect. Remember: it only takes a single shot to the chest, or a shot to the head to take down your enemy. Most weapons (other than the shotguns), are effective for as far as you can possibly see, so don't ever think an enemy is too far away to be fired at- you will hit them!
If you feel you are about to encounter heavy close range firing, you may wish to change out of single shot mode, and into either burst mode, or fully automatic mode; depending on your weapon. Burst mode fires three bullets each click, whilst fully automatic mode fires for as long as you hold down the mouse. These are good modes to use when "spraying" enemies up close or when laying down suppressive fire (explained further on) with a machine gun, and can both be accessed by using the fire-mode key (Default "F").
Be Aware of Your Current Objectives at All Times: A commander-set objective is indicated by the "Crossed-Swords Icon" (when attacking) or the "Shield Icon" (when defending) on your compass. This is your current objective, and what you should be striving for at ANY given time. If you are ever lost because you are unfamiliar with the maps, good advice would be to follow teammates headed in the direction of your current objective. The "H" shaped icon on your compass is your Commander- heading to his position will unite you with your squad if you're ever separated.
Communicate With Your Team!
It amazes me how much more effective a team is when they are actively communicating. Most server networks have woken up to the fact that alltalk 1 is set by default and have fixed it themselves, so there should be NO reason why you shouldn't use in game voice chat to communicate. Tell your teammates where that guy was that killed you, or where you think someone is camping, so that they don't all fall into the same trap!
Taking Cover and Peeking: Keeping yourself behind cover and using "Peek Left/Right" (Default 'Q and E') to see what's around corners is an easy way to stay alive longer. If you think there may be enemys around a corner, go to the edge of the wall then peek around it BRIEFLY. If you see a target, then look down your Sights and peek around the corner again, firing at them. This way you are showing them a much smaller target than if you were fully visible.
If you need to get across an open area, always SPRINT to the NEAREST cover. INS is unforgiving and realistic, in that it is quite an easy feat to take out a target that is moving in the open, so always try to make these dashes as brief as possible.
Reloading:
In INS there is no automatic reloading as you may be used to in other games. So try to be aware of how much ammo you may have left, and Reload (Default 'R') if you're going into a potential hostile area. Be sure you have adequate cover when reloading, as you are vulnerable. Players should note that you do call our "Reloading, cover me!" when reloading, and this IS audible to the opponents- be careful when moving out as they may be alerted to your position.
Picking Up Found Weapons:
Dead players will remain in the game for a pre-determined time, and so will their weapons. If you wish to do so, you may exchange your weapon for another one that is lying on the ground.
When you are within distance to pick up a found weapon, an indicator will appear on your screen (see adjacent screenshot).
To pick up a weapon on the ground, press your "USE" key (Default 'F').
You do not need to drop your current weapon before picking up one that is on the ground. If you have a weapon equipped, it will swap the weapons.
Since some of the player classes in the game currently come with less that desirable weapons, you may want to take advantage of the ability to "upgrade" your weapon. Keep in mind that when you die and respawn, you will enter the game with your class-assigned weapon.
Using a Bipod:
The player Support Class is equipped with a machine gun. Like most weapons in the game, the machine gun has a certain amount of recoil that needs to be addressed. Some weapons, the MG being one of them, can be stabilized by using its attached bipod whenever possible in order to obtain greater accuracy.
When you are prone and/or when you are near an object that is large enough and flat enough to allow for weapon stabilization, you will see the image indicating you can deploy the bipod (see adjacent screenshot).
To deploy it, press the "Alternate Fire" key (Default: "Middle Mouse/Mouse3").
Using the M203 Grenade Launcher:
The Grenadier class has a rifle-mounted M203 Grenade launcher that works in the same way as a bipod. Pressing "Alternate Fire" key (Default: "Middle Mouse/Mouse3") loads a grenade in, and extends the m203 sights. You can then press the "Iron Sights" (Default: "Mouse2") to view the leaf sight.
The two adjacent screenshots show the effects of aiming down the sights. Note that this isn't the ideal way of using the sights but sight elevation isn't implemented yet. You should always keep practicing to get better at using them though.
If you line up a distant target with the "2", it will land just past the car in the image. This is a practical distance to fire the m203 in the current maps.