So I'm kinda bored and came here to start off a guide ... anyway
To earn with my guide you required another alts merchant with lv10 vend to open vend for sale items because most items will be sold to players instead of npc. How you sell them use commands @ss to check current market price and vend it.
As noticed, a lot newbie always asked question such as where can I farm zeny, how to earn so I decided to start a topic for newbie farming guide with my own earning experience.
I think most common farming according to #main reply is farm
1. Farm geffenia with HP/HW for diamond ring and sell with overcharge lv10 merchant
2. Farm at mvp room for OCA/mvp card and sell to other players
3. Farm at moscovia lv3 loot all stuff and sell with overcharge lv10 merchant
4. Farm at thanatos tower for stone of sage and sell with overcharge lv 10 merchant
Above is the most well known method for farming and most players know it I believe,
BUT I never farmed with above methods BECAUSE it is very COMPETITVE. (I don't like to farm competitvely)
I've been played alot of private server and RRO remained with the most attractive custom quests/map/items. Also this is where newbie can find their zeny with custom quests (of course if u dont do research then u are blind and donno how to farm).
1. Farm Drooping Amistr Hat Required Materials.
As everyone known, Drooping amistr hat is the best general headgear in RRO and people will always aim to get one especially for those physical atk job.
1 Bag of Grain
300 Animal Skin
15 Glistening Coat
2 Amistr's Eye
1 Token of Siegfried
1 Clip of Consciousness
notice the amount of fluff and the place where u can get fur. People will be lazy to farm or do quest to get access to the quest place then they will just buy it, this also apply on old Lokians who wanna made a hat on alts.
How to get fluff
You DON'T NEED to kill mobs. Just buy meat and do the exchanging 1meat=2clover+2fluff+2jellopy
NOTICE JELLOPIES are quest required items for http://wiki.rebirthro.com/wiki/Onward_to_the_New_World_Quest
so you can also sell jellopy at the same time for those lazy people and earn some small amount of zeny.
How to get fur
You are required to do the http://wiki.rebirthro.com/wiki/Onward_to_the_New_World_Quest
and got the access to manuk field and farm hilslion for fur, it is a 100% drop items and most people choose to buy instead of farm and it is cashy than fluff even it only required small amount for making the headgear.
2. HP farming (spamming magnum exorcist) u just nid to rebirth and lv100+ is enough not nided to max
a) farm at geffen dungeon3
Loot everything some to npc and some to players.
ITEMS to players:
1. fabric which is required a huge amount for fable silk quest http://wiki.rebirthro.com/wiki/Fable_Silk_Quest
2. marionette doll for cursed ring quest which it will later transform into ring des nibelungen http://wiki.rebirthro.com/wiki/Cursed_Ring_Quest
3. blue herb to creo that want to climb rank/maintain ranking.
b)farm at nif_fild1
Same as geffen dungeon loot everything u got and sell to npc note that most items here is kinda valuable to sell compare to other place especially eq drop from disguise high rate and cashy to npc.
ITEMS to players:
1. ectoplasm,spool for tailoring which is consumable and always need a big amount http://wiki.rebirthro.com/w/index.php?title=Artistry_and_Crafting_System/Tailoring&redirect=no
note that spool is very cashy as the only mob drop them is hyzo.
2. fabric same as gef dungeon
3. Sniper/GS farm at gh(p)(implosion,aenbharr)
note that to farm implosion and aenbharr u will require to complete
u will nid to do both quest before u got access to farm implosion.
What's good from implosion?
Actually implosion loots are all cashy (from my view tho not to npc except burning hair ahhaha...)
1. Bat teeth katar
You will get a lot katar once u start farming just get a ws with job lv 120 and refine it with oridecon if u get +10 then its good sale.
2. Implosion card
Implosion card is always on demand and you always get to sell it
3. Wing of Black Bat
It is for making arrow that combo with coronis wing and I believe most snipe will require to buy some when they dont have time to farm.
4.Live Coal(time taken to sell)
Live Coal is required by metalwork http://wiki.rebirthro.com/w/index.php?title=Metalworking&redirect=no
and believe me u take time to sell it because not everyone need alot amount of it (unlike tailoring) so its up to u if u wan to loot or not but I do collect it and later someone demanded on trade chat I sold 10k pcs just in short.
5. Oridecon(via web market)
Oridecon is also in high demand as it is required for making keris and its like consumable items as long as keris maker wan to get a perfect stat from it then they will constant breaking keris and make a new keris >>> mean they nided bulk oridecon. http://wiki.rebirthro.com/wiki/Traditional_Weapon_Quest
What's good from aenbharr?
1. Mystic Horn
To make use of this items, u required to do quest http://wiki.rebirthro.com/wiki/Tripatriate_Union's_Feud
and this able to make rune strawberry cake which is very popular (woe ppl normally will buy some).
2. Coronis Wing'
Level 4 Weapon and owns benefit comparing to GB(level3 weapon) refine it to +10 then u will earn. (and most cedi sniper will nid it for tier A)
3. Aenbharr card
Some HP/pala will nid it in advance to increase holy damage.
4. Piece of Darkness
well couldn't find the quest in wiki but, it is an items required to change Dark flame (upper) to dark flame (middle), so some people do buy it so they can change the costume to middle.
4. Lazy Farmer Sit and Earn
You will nid to complete http://wiki.rebirthro.com/wiki/Artistry_and_Crafting_System/Handicrafting
and max ur handicraft level.
afterward just make the ring, YOU CAN BUY JEWEL FROM NPC(not asteria/andalusite).
Popular type of ring will be asteria, ruby and topaz, less popular is sapphire and zircon.
You just nid 3 things jewel from npc, fine grit and gold.
Fine grit and gold can buy from player for certain u will require a small investment here before you can earn.
afterward just sit there and trade with the table and got +4/5 ring for sale. EASY.
5. Farm at odin shrine 2 with sniper/gs
You farm skeiggoid at odin shrine and loot silk robe only which mean u nid alot slot for the eq and then http://wiki.rebirthro.com/wiki/Hip_Ribbon_Quest
Need some help with soft silks? Neeve can help you!
Neeve is Niamh's assistant in Amatsu Ribbon Shop (Amatsu 52, 145). She is located in the same building as Niamh, but to the lower right in the building. She will offer to help you with your Soft Silk farming by converting other materials into Soft Silks. You will need to bring her the following items:
1 Silk Robe 
1 Silk Ribbon
She will give you between 5 to 8 Soft Silks everytime you bring her those items. She will be busy during the Saturdays and Sundays(you wont able to find her on Sat and Sun).
Hair Bow is a part of the Hair Bow & Hip Ribbon Combo.
so soft silk is a required of both fable silk and hip ribbon hair bow quest relatively people made hip ribbon will required large amount of soft silk. provided u can buy silk ribbon at pet shop.
You will also sometimes find slave valkyrie and mvp valkyrie here, loot the eq and sell it for some money.
6. Bored with farming? walk around and try your luck/offer farm mining point
There is something called mining system in RRO http://wiki.rebirthro.com/wiki/Mining_Points
which every 10mins will have a pcs of mining point randomly spawn in dungeon. You can warp with warpra>dungeon and teleport around at any dungeon u like and find for it(look alike with mineral but named mining point and constant jumping on same spot not moving) to sell to other players via #trade and party him to let him locate ur location. Careful that u will sometimes being scammed as mining point is free to pick.
You also can offer a single player that u will find mining point for him/her in certain time and pm him/her when u found it.
note: dont review where u r at before u get a pm.
7. Keep cute/nice sprite headgear.
You will be able to get RDC helm from this quest if u successed 50 tickets ^^ which this head give very nice stat (coz u get to choose and it's overall beat out most headgear), the rdc helm sprite(also called heagear's look) will be required u to pay 50m to choose their sprite OR TRADE IN ONE OF THE HEADGEAR(npc take it) AND YOUR RDC HELM WILL LOOK LIKE THE HEADGEAR U TRADED IN(the helm is account bound).
So most people will try to buy a nice sprite headgear instead paying 50m and had a limited choice of sprite. These cute/nice headgear can be priced between 10m-20m as long as they look good then there will be a chance u get a client.
That's all from me, will kindly edit it if I think of more ^^.
GOODLUCK TO ALL NEWBIE AND WELCOME TO REBIRTHRO HOPE YOU GUYS ABLE TO GET ALONG WITH US.