1. Resolution: Go for the highest resolution that doesn’t bog down your hardware. Try D3D versus OpenGL modes at different resolutions for what’s best. If you see a far off grainy little spot one second and die from the evil AK headshot the next, know full well that foe has better resolution than you.
2. Turn Off Background Programs: Kill those utilities sucking resources in the background, like AIM or IRC, email, Task Manager, and RealPlayer. Keep in mind your available resources run the game – if you are short on resources you will loose frame rate.
3. Use That Console, Baby!  Try max_shells 0 and max_smokepuffs 0 for starters. Bind a key to these commands and run it when you enter CS (better yet, throw it into CS config so it runs every time you start up). This avoids taxing your poor TnT card out on menial tasks like drawing those shells bouncing off the concrete. Who has time to look at that during a firefight anyway? I’d rather watch the bodies slumping and twitching any day! Other commands might help, like fastsprites 2 (use this if there is a smokespammer present). A key connection variable is the rate command – play with this to tweak your frame rate online! Try any of the numerous HL/CS sites for more details (http://www.planethalflife.com/cs/guide/console.shtm for example).
4. Use the drawradar command when you lose radar. Radar is you best friend in the recent CS mods (for you NOOBZ, radar was not always in the game – Hell, I miss the days when the Colt had a scope!).
5. Type stopsound or bind a key to it to get rid of all those annoying background crickets and other noises!

A concept born of our earliest ancestors is the use of more than one sense. You need to be all you can be – toss away the notion that you aim with your eyes. No I am not on crack.

Once you are engaged in full view of the enemy your reflexes and weapon characteristics kick in – and that’s about it. Make your eyes are the last thing you use in each encounter.

K, you are playing Dust.  Now suppose you are a CT, and have chosen to rush into position at the left hallway door. As you approach with knife drawn, get the next weapon queued up and ready. Before you get there the encounter begins. Jump a couple of times – the invaluable air-time is a moment of silence you can use to listen for that clever T rushing down at you, unlike the rest of the sheep on his team charging the side bomb site. Foil his surprise with one of your own. You remember your mantra, STOP-DROP-AND-THROW…back off because his AK will tear you up at close range. Toss your grenade blind around the corner to soften him up as you back off – or if you hear his footsteps getting nearer (full rush) you toss short, just to the corner but not around it, as you back up. Time your fire to coincide with the grenade going off.

You must have stereo speakers widely separated or stereo headphones to play CS. If you can’t hear where the sound is coming from you are losing tons of information on enemy position and direction. Let’s supposed you capped [LCK]Knyte as he rounded that corner, and then the bomb was dropped mid hall. One problem, the 2 CT’s who survived rushed out to the T side of the hallway and got slaughtered – one T left. Hint: the Bomb is not an Egg. Do not sit on top of it. Stay where you can pop out when you hear the T pick it up – a weapon change or picking up an item is LOUD in CS.

Do not forget to play head games with your foe if you have the time. Perform a weapon drop while running forward – this makes some intentional noise and picks your weapon right back up. The enemy has just read this article and is using sound to bead in on you. He jumps out and… where the fart did you go? Away from where you made the sound, of course – preferably where you can get this guy’s back side as he is looking toward where he expected you to be. Or try popping out around a corner a couple of times, as if you are planted in that area. Then move away. They may burn up those valuable grenades on a ghost.

Finally, do not get stubborn. CS demands flexibility and opportunism. If you are storming a choke point and meet stiff resistance, an evil sniping bastard freak, or even a stray Homer or two, fall back. Go the other way. Go quietly or quickly but be decisive. Judge relative weapons and try to have a party in the area of your greatest advantage. That means charging a sniper at long range with that mp5 is not your best option. It means use that assault rifle for hit and run bursting on enemies running in from a distance.

M4A1 (CT only) - The M4A1, or "colt" as it is also known as, is as solid a rifle as you can get. In close and medium ranges, full auto works just fine, while at long range, it becomes an easy to use, 3-5 shot burst rifle. Most rifles can burst up to 3 bullets before becoming spray cannons, making the colt an exception. It takes about 8-12 direct hits with this bursting method to kill an enemy with full armor and health, so it's not as powerful as others but the accuracy makes up for it.
Suggested lengths: Close/Medium ranges.
Alternatives: Steyr Aug for Medium/Long ranges

AK47 (T only) - The AK47 is by far one of the most powerful rifles in CS, excluding snipers. It is accurate for two shot bursts, but any more and it becomes a spray machine. Full auto is preferred at EXTREME close ranges, as the recoil of this gun will not effect point blank combat. However, in medium range combat, two shot bursts can get the job done with only a few direct hits killing the target. Keep in mind, one headshot and they are gone.  For long range, try single shot bursts. It's that simple. Time yourself, and put about half a second in-between shots to maintain good accuracy. This rifle is good at any distance, but will take time to learn how to use properly. Don't full auto..it's just wrong. This rifle was meant for bursting, not spraying.
Suggested lengths: All
Alternatives: Sig for zoom capability.

Steyr Aug/Sig (CT only, T only, respectively) - These two rifles are deadly at medium to long range, but lose their power at point blank. For medium ranges, don't zoom, as it decreases your rate of fire, but burst with 3-4 shots. These guns can take an enemy out in 8-10 hits, making them a deadly addition to the CT and T arsenals. They are essentially the same. You may think otherwise, but the stats are the same for both rifles. At long ranges, zoom in but do NOT full auto, as your accuracy is decreased considerably after 8 shots, even with the decreased rate of fire in zoom mode. Try bursting like you would with an AK at long range, maybe a little faster though, like every third of a second. Get a feel for these rifles, as they are killing machines for almost any map.
Suggested lengths: Medium/Long range
Alternatives: M4A1 or P90 for close range combat

P90 submachine gun - The p90 carries a hefty clip of 50 bullets, making it invaluable at close ranges since you won't have to reload as often. At long ranges, the gun can become VERY frustrating, as it is accurate up to medium ranges only. However you can fire full auto and due to the VERY high rate of fire, you will hit the target pretty well. At close range, aim for the head and hope that those ill 9mm chunks paint a nice red picture on the wall =).

M249 Saw Gun, or PARA - This expensive beauty should be treated just like an AK, as it is almost as powerful but 100% more intimidating. Try bursting single shots at long range every third of a second, and just spray it through boxes as needed =)

MP5, U.M.P., and Uzi's are all full auto at any range, as bursting does not improve your chances of hitting the target nearly as much as the above guns - PS. If you use the Uzi's at long range you're high.

Reloading

Most guns don't take all that long to reload, with a few exceptions. The Steyr Aug and PARA are the two guns that will get you killed while reloading the most. When using guns other than the PARA, with a 30 round clip, try taking out an enemy in 10-15 hits, leaving the next 15 bullets for the next guy, therefore taking two men out before the need to reload. When reloading, duck behind a box and get ready to pull the 9 (sidearm, for u n00bs who don't know what bust a 9 means). I suggest moving around while reloading, like swirling, jumping, stuff like that. With the PARA, reloading should be done in a secluded area and out of sight. The chances of you using all 100 bullets though are slim, unless you spam someone.