when fighting a player in ET remember to never stay in one place, which could lead to a lot of bullets that have been fired hitting you as it's easy to shoot and hit a target if standing still. Also if you decided to try and sprint away, always run to the left and right which links back to before.
Never use a grenade when fighting a player because if the grenade harms you instead that gives the other player an advantage in defeating you. If you are always the one who attacks in ET then make sure to never use pistols and only if ran out of ammo.