First thing Making More Zeny Depends on the server you playing and The drop rates.
Hunt only the following things if the drop rates are good(higher than normal).
Gokurin-Selling Price 120,000z with over charge 148,000z -Droped By Petite(Sky Petite)
Also Try To Hunt If Server Have Market for following:-
IF People Buying some type Equipments every time Then Try To Hunt them always if it gives good zeny.
IF People Needs Lot of Elunium and Oridecons then hunt them always if it gives good zeny.
IF People Buy lot Of Blue Potion,White Potion or Condensed/slim potions then Make One Dex/Luk BioChemist.
If People Still Buy lot of Very Very Strong Weapons Made By Blacksmith and White Smith then make one WhiteSmith.
Try Refining Luck…If your real life luck is good then upgrade equips and sell it for higher cost.
Buying & Selling:-
This the important Step For Earning Huge Zeny Profits. Spend 1-2hrs in Market Area and Earn lot.
It Works like this…just buy any good stuff for lower and sell it same for higher. Many Ingame Rich People Do Same..And it Really works..i Personally Do This In Every Server.
Dream To Make 100million zeny or 1Billion Zeny is not Hard at all (My highest zeny was 56billion on 1 server made in 2months and Equipments worth 75billion+).You just need to use common sense and find the way to make faster zeny by hunting or buying & selling or By Refining.The Best Thing is to be active in market and keep looking for good deals always.Even on low Rate(official servers) you can make 1billion within 1month easily and if you are good enough in business then you can make upto 10billion.
Always try to Find out what is rare and what is sold more in your server and hunt for same.
Zeny is not Everything but its always useful.Zeny is not important in many server where market is not that much active and good on such servers i will say to only concentrate on your equipments.
After Having Enough Zeny you can Start your own Guild with 70+ Members by paying them higher salary than others and fight for you (this rocks!!! all will talk about you every where)
Donating to server is not Required as you can earn faster zeny and buy same donation Equipments from others in exchange with zeny. /GG
Happy Earning Zenny ^^
Thanks For Reading ^^