Monster Carnival Everytime you see a maple coin, go get it. Do what you need to. Steal maplestory mesos, kill the mob for them, whatever you feel like. When you have , talk to Spiegelmann and buy the highest level items you can(level 40, I think). Do some research and see which weapons NPC for the highest cost. 50 coins could rake in over 1mil. And this happens while you train so speedy exp and some respectable mesos.

Quests Lots of quests give great rewards. playing through the game and finishing maplestory mesos quests can give you mesos to buy potions, weapons, and armor. Quests can take several hours to complete and they dont always have the best reward. I recommend you look up the quests before trying them.

NX money Now this is an effective, but dicy system. First you need around 10k NX. Go to Mushroom Shrine (Zipangu). I dont know if this is entirely true but i have heard that you cannot have any items on the ground or any other people by you when you use mesos maple story Gochapon or else you will receive items that are not worth much.