Don't just practice in the VR, use it to determine your ideal mouse settings for crosshair, ADS, scope, vehicle and tank guns, and aircraft. There is a distinct reward to being obsessive about this for an hour or two, obsessively tweaking your sliders up and down one notch at a time until each interface operates smoothly and instinctually. Don't just idly shoot the targets, either. Try things like switching from one target to another in between shots or bursts, moving erratically while shooting, toggling ADS on and off between targets or even between shooting and moving, stuff like that. Don't be afraid to adjust your settings in live, either, if you find yourself making a particular kind of aiming error consistently (like over- or under- correcting when moving your sights onto a target). Once you've got it adjusted so that your instincts aren't fighting your control scheme, your aim should improve more rapidly with practice. Framerate is a big deal when your targets are live. In VR, turn your framerate on with Alt+f, get in a Lightning with Viper cannon, and drive around shooting full auto at the ground directly in front of you. If you see your framerate drop, it means your system is stuttering whenever it renders weapon hit efffects, and it will likely also drop frames when you're shooting at enemies close up in infantry combat (which will throw off your aim). You'll need to turn down particle effects and rendering quality until you don't see that effect anymore.