Live alone. Independence provides a fuckton of experience points. It lets you figure out what is important to you, and it teaches you better ways to sustain yourself efficiently. That's effective EXP grinding right there. Responsibilities (feeding yourself, paying bills, managing your time/energy/finances) also pop up when living alone and these become part of an experience-generating routine. Eventually, you'd become comfortable with the routine that you've set for yourself. And when it gets too comfortable and monotonous, you'd want to take break from that routine via travel, hobbies, and whatnot―which lead to more experience points. Living alone, man. It's basically power-leveling.