ALWAYS have all your skills and abilities on your bar. Read the tooltips on your spells/weaponskills and abilities too. So you know how and when to use them. That should hold you over for most of your leveling. And once you get to a point where you are higher level (DEFINITELY do this at max level) look over some info on your job online to make sure you are doing it correctly and not missing out on tons of potential damage. Because, as a dps, you need to try and be efficient with your damage output. Otherwise you're just getting carried through content. And you'll hit a point in this game where you will not be able to progress because of that.