three-boxer on Brandywine here
I've been playing LOTRO since August, and two-boxing and then three-boxing since September or so.
I use separate installations on three computers, so I'm not sure how to go about doing multiple instances on one; just haven't had to learn. I use Synergy to pass the mouse back and forth, and Multibox to broadcast keystrokes. The main character uses 1-=, the char on the left uses F1-F12, and the char on the right uses the number pad, so by using shift, alt and ctrl, I can set up to 4 rows of quickslots easily.
So far I've run a group with Loremaster (main), Guard and Minstrel up to 50, one with Burglar (main), Captain and Hunter up to 50, and my current set is Champion (main), Guardian and Minstrel, and they're in the low 20's. Of course, the ones that are now level 50 I mix and match as needed.
I get the impression from this site that multiboxers prefer running groups of the same type of character, preferably at range, but I have to say LOTRO works pretty well with balanced mini-fellowships, and in melee as opposed to all ranged. If I had the resources to four-box, I would add a bit more DPS or healing as needed and could probably do most of the group content, as well as just flying through the solo stuff.
My original intention was to get one of each class up to 50, and then use that character solo for endgame stuff as needed, but recently, I've two and even three-boxed some of the stuff like Carn Dum, Urugarth or the Rift with the rest of the party being made up of kin-mates, and it's actually gone pretty well.
If anyone finds themselves playing LOTRO on the Brandywine server, send a tell to Slartibartfasto or Belloc, I'd be glad to chat. Also, much as this site helped me put my setup together, and much as I value this community, I'd be eager to join a more LOTRO-centric multi-boxing community as well.
