Swift Disarmer (3.5e Optimized Character Build)
From D&D Wiki
A low level disarming build made to be effective, without needing spell enchantments or ridiculous magic items you probably won't get a hold of for quite a while. This build is primarily a rogue, but uses one level of fighter to get the extra feat at first level. It also gains the benefits of being a rogue, so you can have a stealthy disarming character.
Uses only the core rulebooks.
 Game Rule Components
 Spells, Powers, Soulmelds, Stances, etc...
Part of the point of this build is to be practical, and not rely on wasting a bunch of buff spells or having to get magic items that you really wouldn't get at a low level if your DM is really really generous.
Spiked Chain or Whip are required for this to work, for their disarm bonuses. A spiked chain would be best since it can do lethal damage and damage armored enemies. But I know some people think the spiked chain is overkill and shouldn't be used. You could use other weapons that have a trip bonus, but they either don't have reach or aren't finessable.
If you use a whip then it would be a good idea to have a second weapon that is finessable (I'd use a rapier). As mentioned above whips aren't meant to do damage, so a weapon that is would be smart to have. Disarm, then switch.
A ranged weapon such as a crossbow would be smart to have as well, since you can disarm from a distance with a chain/whip, then shoot or throw from a distance.
Scrolls. I said this wasn't meant to Rely on magical enhancements, but you can as a rogue get some benefits by buying scrolls and using "Use Magic Device". It's not necessary but if you want you can cast some spells to enhance your BAB?
Aside from those recommendations the usual rogue items are a must. Light armor, tools, grappling hook, rope, etc.
Starting Ability Scores (Before Racial Adjustments): (From a 30 point buy) 10 STR, 18 DEX, 8 CON, 14 INT, 8 WIS, 14 CHA
Race (Templates): Human
|Saving Throws||Feats|| Class
|1st||Fighter 1||+1||+2||+0||+0||Exotic Weapon Prof. (Spiked Chain/Whip), Combat Expertise, Weapon Finesse|
|2nd||Fighter 1/Rogue 2||+1||+2||+2||+0||None||Sneak Attack +1d6, Trapfinding|
|3rd||Fighter 1, Rogue 2||+2||+2||+3||+0||Improved Disarm||Evasion|
At early levels this build can be a great ace in the hole and with the rogue skills disarming in combat isn't the only thing it can effectively do. The one level of fighter makes it possible to get all the feats needed, and overall the fighter compliments the rogue levels. The big downside is that at level 3 it has only a +1d6 sneak attack. But you most likely won't be using sneak attacks to much with this build, because it adds a new spin to disarming. You can have your rogue/fighter sneak past the enemy, disarm them, and then have the rest of the party pop out and attack. You can throw their weapon aside before the fight even begins! And with +10 to disarm checks (+2 BAB, +4 DEX with weapon finesse, +2 whip/spiked chain bonus, +4 improved disarm) you have great chances of succeeding at lower levels, and with Improved Disarm you don't risk getting yourself disarmed.
 Side Notes
This build could be done with an elf instead of human to get that extra dexterity, but it means you'll have to wait till level 4 to get all the feats since you won't get the bonus human feat and you'd have to take two levels of fighter. But you get +12 to disarm checks at level four, whereas a human with the original build would have +11 at level 4. It also means though that you would still be stuck with 1d6 sneak attack at level 4. It's personal preference really.
This build works only against armed opponents. If they have natural weapons it obviously won't work. But you still have the rogue skills. And if you take spiked chain you have an overkill weapon at your disposal, which at level 3 of this build would have +6 attack. So it's not rendered useless in such a situation but the main point of it doesn't matter. It also requires every feat from levels 1-3 to be dedicated to disarming. Doing it differently to save a feat would make it less effective at this specific task.
 DM Counters
Use creatures that use natural weapons, and/or throw in the occasional npc monk. NPCs could also have locked gauntlets, which add +10 to checks against disarm attempts.