I have decided to remake this post with the contributions of many other members of the Caitsith family.
Below are some points to keep in mind when farming that will help you maximize your income. ^^
Locating a location - I personally believe that you should never farm in an area where mobs can aggro you. (Excluding NM Pops) Every mob within the area should be TWTBW (Too Weak To Be Worthwhile). Having to worry about EP or DC mobs slows down production and makes it quite a hassle.
Know your Area/Zone - Get to know every zone in terms of what spawns, when they spawn, where they spawn, and what they drop. With this, you can develop a game plan.
Travelling to and from your Area - Outposts. Use them. I like to farm zones that my country controls. Why? First, easy in and easy out. Second, when my inv fills up, instead of dropping items, I can run to the outpost and sell off items that I would normally unload onto an NPC. Got too many femurs or hides? Run to the nearest outpost and unload a few or teleport back to your city to move them to mule or AH.
Subbing THF - This is really a no-brainer. Make sure your THF is as least level 15 so you have both Gilfinder and Treasure Hunter 1. It does make a huge difference. If you are farming a wide area and are at least 50, Flee helps out a great deal as well so THF at 25 would also help.
Staying Alive - The worse thing that can happen is dying while you are farming. Know your limit. I would recommend that if you get deep into yellow, do something. Last resort is resting. If you are a mage, you know what to do. For other jobs, you could use bloody bolts with your Ranged Attack to pull HP, or if you are a MNK, make sure to Chakra often. As well, you should use abilities/spells like Utsusemi, Dodge and so forth if you have them to reduce your chance of getting too low.
Valuing Items - Know what prices your items are going for in the AH and from an NPC sell. This is also imperative for managing your inventory so you know what to keep and what not to keep if you run out of space.
Stealing Items - Did you know you can steal certain meat from tigers? Did you know you can steal tears from Ahrimans? You can also steal giant bird feathers from Tabars. Do your research and see what else you can get from these mobs to maximize your farming income.
Claiming your Mob - This really depends on how camped this area is. If it is not very camped, just SA and attack the mob from the back. But if it is pretty camped, then you definitely need some sort of mechanism to claim a mob quickly. For me, I swap between Chi Blast and Steal. Unfortunately, I have to get up close to the mob for Steal, but it is quicker then waiting for the attack delay. For mages, this should be cake since you can use spells like Dia, Flash, Stun, etc. As well, make sure you check the name of the mob, before you attack it. Many times there are locations where NM's will spawn and look identical to normal mobs.
Farming Courtesy - Really, this doesn't apply to the gil sellers. However, in some places I farm, I see people there regularly. I try to be courteous with them, like if I see them about to engage a mob and so forth, I will let them have it instead of trying to out-claim them. On the other hand, if the other farmer is being a prick, this doesn't apply either. But keeping this courtesy with the nicer farmers, they generally will do the same for you, at least in my experiences. Also, you never know if you get a link or if you start to get in trouble, you can either invite another farmer to party or call for /help.
Managing Inventory - For me, I have 50 slots available (still haven't done the last GB quest). I always, sort after every drop to make sure nothing is lost. As well, I always recommend to keep everything and sell everything. But if you are running out of room, drop the crappy items. This is where knowing how much the items go for in the AH and by NPC's comes in handy.
Patience Needed - On many game days, you will see that drops don't occur to often. Have patience. In the places I farm, the best days are usually Windsday and Waterday. So there may be periods where it is dry, don't stress. Just keep on trucking. Farming was not meant to be easy.
Long-term Farming - Don't expect to make a lot of money in one day of farming. However, I would make a goal depending on the area. Whether it is 10k or 100k. As well, you will probably need to farm for at least 3-4 hours to see a decent amount of loot. 30 minutes of farming won't get much at all.
NM Camping over Farming? - Why not NM camp and make the big bucks instead of farming for hours? Well, this has always been a toss up for me. But it depends on how you play. I have done both, and been successful at both. I have also failed miserably at both. With NM camping, expect not to get a dime for hours. But, if you are lucky (since NM camping is based on 90% luck, 10% skill and know-how), you could score a huge drop.
As well, if you are going to camp an NM, in between spawns, you could always farm mobs in the surrounding area to make something, so it is not a complete loss. For example, in Oztroja, you can farm Crabs, Crawlers, and Yags to make something while waiting for Mee Deggi or Quu Domi to pop.
Dealing with Gil Sellers - Dealing with Gil Sellers a.k.a. MOB monopolizers. This is a rough one that I have been going through a great deal. You really only have 3 options here:
a) Deal with it and try to farm what you can.
b) Pick a new area.
c) Bring another person with you to increase your chances of grabbing mobs. You may think, well, you don't want to share your farming. But it is certainly better then getting practically nothing from going with option a.
Diversification - Have multiple farming zones. Why? If a zone is overcrowded, you have backup plans. No need to waste a day that was planned for farming.
Special thanks to the following people for contributing ideas on the original posting of this: Heylee, Deadmeat, Narel, Galkalord, and hXcHillary.
Any comments or concerns? Please let me know. ^^
Edited, Tue Dec 28 15:41:25 2004 by DJSlyde

) for our farmers to take into consideration.
as well,