UT2004 is a very fast game and mastering movement and speed is crucial. There are multiple ways of movement, but the most common is the WASD technique.
Movement & Movement Keys
The default movement keys are -
- W , ↑ = Forward
- S , ↓ = Backward
- A , ← = Strafe Left
- D , → = Strafe Right
The most common keyset of movement is by using the WASD keys. This way, the user is able to quickly access other keys, such as Space , C , Q , E , etc. The Arrow Key movement system is not recommended, as it leads to inconvenience, especially in Onslaught or Assault matches, which require multiple keys. However, if you do choose to use the Arrow Keys, it is easiest if you set Shift as your crouch and Ctrl as your jump. This allows you to keep your left hand nearby all of the necessary keys and the only keys which are excluded from your reach would be the number configurations for switching positions in vehicles.
The number one tip given to all players is to constantly keep moving. Standing still makes the player an easier target. Constantly moving, especially in unpredictable patterns reduces the likelihood of an enemy lining up shots.
Another common tip is to "run laps" around the map. This means running around the map in a particular course. This course should cover most important objects such as Shield and Health packs. This way the player can constantly stay ready for action. This technique is used best in Deathmath matches and its variants.
Looking
Looking is achieved through the mouse. Pushing 
upwards will make your view (and, in turn, aiming) turn upwards. Pulling downwards makes you look down. Similarly, moving to the left or right will make the character turn to the left or right. You can invert these controls by going to Settings>Input>Invert Mouse.
Keep turning at all times to get the widest view possible. If you are engaging an enemy, keep turning your mouse so that it is constantly pointing towards the enemy. You will know this is so if you see the enemy player's name below the crosshair in green. This requires practice, as it is difficult to maintain the aim while moving or dodging.
Circle-strafing
A common technique is circle-strafing. This involves using the strafe keys to move around while keeping the crosshair fixed on the target, thus making the character move in a rough circle. This technique allows you to move to another while still dealing damage, and can also reduce the chance of being hit by the target or another opponent. Making the "circle" rough and unpredictable will decrease the opponent's ability to predict your position.
Jumping
Push jump in order to jump. This is necessary for reaching higher surfaces and also makes you harder to hit, especially for headshots. Players crossing the map while jumping incessantly is not uncommon. You can also double jump to jump even higher.
Crouching
The Crouch key ( shift by default) allows you to get as far out as possible on a ledge without falling off. This only works for building ledges and cliff ledges, not on a Manta's side or any other vehicle. This also makes you a smaller target if you're camping.
Dodging
Dodging is a very useful tool to get somewhere on the map a little faster (if a vehicle is not around), or to dodge enemy fire. To successfully 'dodge', you must double tap the key of your choice depending on the direction you wish to go.
Double Jumping
Double Jump is a useful ability to get to a higher edge that jumping once just will not reach. In order to double jump you must first hit your default jump key, then at the peak of the jump you must hit the jump key again and your character will get an extra boost into the air.