SPAWNING
Ok first off you get into a game and you spawn, well a lot of people make the mistake of running for health while other skilled players run for weapons, reason being if you catch an un-armed oppenant you will rape them blind. So when you spawn at least grab a weapon of some kind, or if health is really close and you are fairly sure you will not run into an opponant, just grab it real quick and head for a weapon. Also when you have just spawned, if you hear a whole buncha wang bangen goin' on, steer clear. If someone is being 'cheap' and using the 'sticky bomb respawn' tactic don't even bother with a person doing that unless you are just kinda fooling around, that type of thing is lame.
LOADING UP
Once you've started and you have weapon of some sort, you should probably try to load up on goodies, particularly armor and just kinda move through the level at random or to key places when you need something (Like heat seeking card). Always try and maintain 50 armor, and 150 health, that way if you run into a battle, you can take some abuse.
WEAPONRY
Ok so you have started and got some health and some weapons, among these weapons you should always want to carry a:
Missle Launcher, often the most favored weapon by expierenced players due to its ability to inflict X-Treme punishment in a speedy package. The missle launcher is a good weapon you should learn well, learning to aim it is a bit of a struggle sometimes but you will learn to aim it well over time. The heat seeking card is probably the most valuable asset to the missle launcher, it will track your oppenant but isnt a sure fire kill.
Use this weapon in close quarters also or long range with the heat seeking card.
The Grenade Launcher is a good Secondary weapon because it can reach hard places that the Rocket Launcher cannot, (In a deep crevice where you cannot see straight into it is an example) The grenade launcher is an extremely powerful weapon, If you are in a FFA battle, and you see some players fighting, lob some grenades into the fray if your low on health to aviod coming into direct contact with the fighters. Dodging the fire from this weapon can be tough but since it takes three bounces to explode, you shouldnt have that much trouble. I refer to the Grenade Launcher as a newbie weapon quite simply because only newbies seem to use it a lot. This weapon is best for flushing people out of somewhere or forcing them into something.
Railgun, This weapon is a very powerful and very deadly in the hands of the right player, Aiming this weapon isnt to hard, but dodging it is tough, When your aiming it all you really have to do is put your cursor near the person and fire and the games build in A.A. will track the person and hit 80% of the time. Dodging it is fairly hard since it is AA'ed. You learn different techniques that throw off the A.A. over time, lonng periods of time. If you are low on health and your opponant has the railgun and hes out on the open, try and stay away its an easy frag for him. This weapon is best for open areas.
Riotgun is a very effected close range weapon, using the secondary fire of the shotgun will rip through an opponant if they have low health, if your attacking a skilled person with the riotgun, its pretty useless if they arent softened up with a rocket, its just like a bunch of mosquitos. Use this weapon in close quarters on opponants with low health.
Gaurdian Head, Easily the most powerful weapon in the game, with its second function, in a close area it will kill any oppenant within 3-4 seconds easy. the 3rd and 1st function aren't very good but the 3rd function is good for spamming a big battle from a distance.
FRAGGING YOUR OPPONANT
So you've got your weapons and health, now you gotta use them in an effective manner, by this I dont mean sitting in one spot, spinning, and holding fire, I mean that you have to learn to aim while moving and jumping. You maybe can kill small animals if you spin and fire, but only newbies like ray222 will try something that stupid. You should learn to predict where your oppenant will go, and which way he will be getting there, like if you have hit your oppenant with a rocket, hes probably gonna be looking for a cookie nearby so make sure you keep him from getting it. Also, as you play more and more, you will notice where players like to go so, by taking a shorter route, and by running faster with the ALT strafe/run you can cut them off. After you have killed your opponant you will want to 'Hog' all the items and weapons, you should know that after you frag someone, they are gonna be looking for some weapons and health, well make sure you hog these items and keep your opponant weak, thats how we like, right? ;) The name of the game is domination after you kill your opponant, you will want to actively seek out your opponant and kill him while he is weak, but make sure you can take some punishment too, (You dont know what theze fists can do).
STAYEN ALIVE
Well in order to keep from getting fragged, your gonna have to learn some sorta of dodging technqiue, whatever works for you, some people like to use circle strafe to dodge, (If you arent using some sorta of strafe, you can might as well kiss your ass good bye) others use ALT-Run, I prefer alt run because the winder can circle strafe by twisting it, and I like the alt run for extra speed. Never run in a straight line, you dont have any idea how easy of a target that makes you, plus you run slower like that. When dodging heat seekers, you need to run in a circle, or turn in some way to that will make the heat seeker turn also, the heat seeker is like 5xs faster than you when its going straight, but like 5xs slower when your turning, so run near a wall and it will turn into it.
Thats about all you really need to know, you develop your own little tricks over time,
go to http://www.Kali.net and keep SW alive ;)