In a lot of games, I find there there are little elements of the gameplay mechanics that aren't tied to the plot and readily apparent, but extremely helpful to know. For example, in Dead Space 1, enemies only tend to drop ammo for weapons that you're carrying at the time.
Considering how much of this game is about exploration and figuring things out, I'd imagine that there are a lot of subtleties that can smooth things out, if you know what they are. I don't know if this would count, but one thing I didn't realize until a little while into the game was that when you're wielding a gun, you can hold up or down to aim at the enemy's head or legs. Since you're shooting at an angle, they need to be fairly close, but the shots that do land will respectively do more damage or stagger the enemy. It can be helpful to save a few bullets here and there.
Anyone else have any general tips?