how to level up
Play moar
Well it all depends on what you like to play. If you like to play solo or with a small group of friends then spartan ops is for you, but if you like to play against other players then war games are for you. Another good thing to do is to find a good load out for you. Try out different combos like for instance if you had DMR as your primary then you should try the boltshot, but if your feeling lazy then go to halo waypoint and type in some codes for xp. P.S. some codes need you to complete certain challenges for you to unlock them.
Unlock the Pioneer Specialization and equip Fast Tack for extra XP.
Play a gametype that you are good at and that is relatively quick. For me, that gametype was SWAT (also the Fast Track specialization)
H4 is probably the easiest game to rank up. Took me about 2 months to 130
JUST PLAY SPARTAN OPS
you can lvl in war games or spartain ops or halo waypoint on your consle and look up halo waypoint codes they are pronithian writing and they get you xp and armor sometimes even embelems