I burnt myself on the deep fryer at my job on the underside of my wrist. What should I do to advoid scaring?

Bio oil. Once healed bio oil or silicone gel or mederma will decrease raised scar tissue. Since this on a joint compression with a wrist support can decrease the tendency for raised scar formation.
Keep it clean. Keep it clean, apply polysporin (bacitracin and polymyxin) (avoid neosporin; it's highly allergenic), and watch for infection. It's probably best to also keep it covered with telfa, a non-stick dressing, especially when at work. A thin layer of polysporin (bacitracin and polymyxin) aids in healing thus helping to minimize scarring. Unfortunately, nothing will prevent scarring completely; this depends on your body's natural healing abilities.