I keep to the same keybinds and hotbars I started using in 2007-2008 in WoW, no matter the MMORPG, so long as it's possible (things change slightly in action MMOs, but it follows the same theme). It is incredibly convenient to learn new classes/jobs/games this way, since despite differences in execution of abilities, so long as it's on the correct keybind, I will roughly know what it's going to do. It helps track cooldowns as well, and you'll quickly know the class's weaknesses because certain keybinds will remain empty.