Best way is playing the market. Buy stuff up cheap and resell it.
In order to do this you need some money to start out with tho. But by far the biggest amount of money i gain out of it is the market.
A good second one is merit badges farming, put vip on your account and drop it full with low ti merit badge farmers. I got 6 on my main account which gies me about 15m each day, with the other 2 side mains of mine i get another stone which brings me up to 19m a day. Super easy and super stable income. ( 130m a week ).
Other then this you can get a backpack and greed your way through ti party's and sell it to npc's with overcharge merchant, or orc dungeon 2 which is also a good place.
If you don't want to do all of this and gain fast money for gear, your best bet is to plump in 100/200 euro's/dollars into warpportal points and sell that off with boxes through a merchant. Brought me my first cash where i later on played the market with.
On how you play the market, just check items that are cheap but sell high with refinements like +7 waepons are 100m more then the +4. then just refine it yourself to +7 and you will get on average 20-30m as profit out of it. as it mostly costs me 5 refinements to get +7.
Once you get more money and hit a billion, buy all kinds of +7 items or +0 items and refine it to +7, then when refinement event comes plump all your money into enriched ore boxes and refine all your gear to +9.
Then wait for the event to stop and wait 2-3 weeks, and you can sell it probably for double the price you invested into it. This can create you easily 1billion with a 500-1b investment. So basically more then doubles your money.
You can also see if people are in a hurry to sell something as they need zeny, they mostly undercut there item massively for example lowest price has been 280m for a item, he sells it for 200m. He wants to get rid of it fast. You buy it up and put it on there for 280 and just leave it in your vendor for a week. at some point one will buy it = 80m profit without doing anything.
Farming for monsters and drops is all complete rng, you can have zero chance to get anything in months. Waste of time. Same thing i find with hunting mvp's. People get maybe a card once a year but farm them daily for multiple hours. Not worth it at all, if you calculate there expense + time they spend on it you are better of playing the market.
edit
Also what i often do is, invest into gear for my characters. For example if i need a item for my main character i will try to cut the price as low as possible. I will look over multiple days or weeks if somebody is selling one for cheap and once it's cheap ( or trade items that i bought cheap for that item ) i will buy it and use it.
The moment i'm done with the char or with the item, i can always resell it for way more. This is how i got a autumn headband +9 for 375m, and sold it off later when i didn't needed it anymore for 575m, 200m profit without doing anything.
Don't be impatient and buy items for high prices, just wait it out and make sure that every item for any char you buy from your farmed money is going to make you a profit the moment you want to resell it. This way your overal money pool even when you buy items will become bigger and bigger over time.
Edited by gatygun, 07 April 2016 - 10:04 AM.