Ok second tip:
Take advantage of the topography of the land. If theres a ditch, hide in it. If theres a hill then by all means climb on top of it. Don't climb trees though, thats kind of dangerous and it's really easy to shoot someone climbing, or in a tree. Use nature and your environment around you to an advantage. I'm not saying to get all Rambo-crazy by chopping down trees and making spike pits and crazy stuff like that, just use the environment to your advantage. If you're playing in the woods use the trees and shadows to hide in. Trees make natural alleys and path ways that people are forced to walk between, providing oppertunity for an ambush. The narrowing of two sides of a valley creates a natural barricade and point of ambush where people have to cross between. If the ground is uneven then use the fact that your opponents will not be able to move very fast and ambush them. High ground is better than low ground because have a better and farther field of vision. You can duck and hide in tall grass. Hanging tree branches often times splatter paintballs before they can reach their destination. Use bodies of water as natural barriers. Most paintballers are unwilling to ford a river just to win a game, so use that to your advantage. You can easily make a fair seeming woodlands game turn into a one sided paintball slaughter if you just use the advantages nature provides.
And no, Magnus55 is not a hippie.