The only 2 bits of advice about stick welding that ever seem to make a difference to me:
1. Arc length is crucial. Undercut, especially uphill is more often caused because you lose contact with the base metal. 6010 I run "scraping" the base. The deposition rate is so fast, you need to stuff rod (this is a characterization not a technical term). Its always been a harder rod for me to run than 70xx, because I can read 70xx puddles more easily.
2. Whatever you do the left side, you do the right side. Depending upon the direction or hand you weld with, you will always have a "strong side" when welding. So I force myself to count in my head, even still, to keep my rhythm and timing on both sides of the weld. Even on a "forward and back" I use this method. It has produced more consistency for me, and kept me away from a grinder and closer to a stinger are than I deserve.