Get in range of the creature, and start blasting. Overcharge shot, kneeling, kiting (shooting it as you run away, to avoid getting hits) are all valid tatics. Experiment. The newbie monsters shouldn't be that hard. Tatics are important in this game. Some may say that you should just �spam your best damage attack�, but if you learn to use tatics, it will help you much more in the long run. Remmeber, if your using a pistol, get in close range. Carbine, meduim, and rifle, long.
Being a Brawler
Whew. Glad I don't have to type all this again. Read the marksman section, and suppliment the last paragraph with this: