My feedback would be:
1. work on getting a consistent bead with, by not progressing the torch forward until the puddle has grown to your bead width "target". Keep the same width "target" throughout the weld for uniform weld bead width. You don't have to constantly stare at your puddle to do this, you can use your peripheral vision to see it as well.
2. similarly use the height of the bead to judge when you've added enough filler rod and try to keep that consistent as well.
3. work on running your beads in a straight line. Most weld joints are going to be in straight lines, or at least careful control over the path. I would practice running your beads parallel to one of the cut edges. Which brings up another point, make your cut edges straighter to give you a better reference while welding.
4. to reduce oxidation of your weld joint, try using bigger coupons to conduct the heat away more quickly. Or, try running smaller weld beads (switching to a smaller filler rod if necessary) for the size coupon you are using.
When you feel like you've gotten your fill of running beads on flat stock, next step is to join two pieces together in a butt weld configuration.
'13 Everlast 255EXT
'07 Everlast Super200P