Nobody mentions the rocks! The almighty rocks are so much fun! Use them to control your enemies, both to make them look away from somewhere and to lure them to ambushes. Remember to not spam them too fast or they'll start to doubt and search in different directions. It's best to wait until they arrive at the sound position and start looking around to throw the next. Use the bushes, they'll hide you perfectly. Get the fast crouch movement perk asap. Think about distractions. Rocks work great but a well thought gunshot or explosion can lure all enemies in one direction and reveal their positions, as long as you don't reveal yours. Fires can be useful too, but use them carefully, they'll get their attention but lure the enemy away from them, making it hard for you to find a new position. Get the perk to move corpses after a takedown and make good use of it. As for weapons, the bow is very powerful and you can retrieve arrows, but it's slow for my taste. The Bushman and other automatic silenced rifles are personal favorites. As mentioned before, a silenced sniper rifle is an almost too good option, but also fun on it's own way. Remember to still change your position after you shoot, cause they'll still know where the shots come from.
That's all I got for now
EDIT: wow what a wall of text I wrote...
http://goo.gl/Wg6w0 "=[_]=! Bump some other boobs, will ya?!" - p "That sounds so perverted, dude. ._." - M