Keep your arc length short, your tungsten uncomtaminated, and your grip on the torch soft. Weld the left handed part left handed. Dry up the puddle before snapping out and never snap out over the root pass, get on the bevel face first. Don't spend much time on 6G at the exclusion of 2G and 5G.... some guys in some schools practice way too much for test welds, but overall competence needs to be the goal. When you get good in the open, add restrictions to your access.