First up is a great article by The Ferret on Star City. How to Be a Mediocre Player contains lots of things even casual players need to pay attention to to get an edge without going full-pro-style. It was written back in 2007, but it's still relevant now. Excellent, simple advice!
Also containing the word "mediocre" is Seven Deadly Sins of Mediocre Magic by Michael Flores. This contains even more tips, but they are mostly directed towards pros and pro-hopefuls.
Enjoy!
