Started playing 8 months back and still playing!
Always go for good gun and gain two gun for the advantage I always go for dual guns which are very effective any situation of the game.
But sniper and shot gun makes an effective combination another good combination is shield and revolver.
Check your weapons and keep it full loaded before you go to the battle
Try to maintain your rocket fuel full whenever possible .
If you get hit try to hide to regain your health.