Here is a small guide, much like the one on Dulfy, to do the daily Orphan Run in Divinity's Reach. With this run and all of the karma boosts listed below, you can get about 3,500 karma per orphan per day. That is 105,000 per day for about 5-10 minutes of work. Bare in mind the amount of karma you gain will vary because of the karma gain you get from your achievements in the hero panel. (In my case I have 21% extra karma from the achievements so I get 3690 karma per Orphan).
I suggest you dedicate a Character on your account to do only this, that way the buffs you apply will remain as long as possible. (If you don't have mounts, Mesmer is probably the best the use with the Blink ability and set it to have a faster cool down) If you apply these buffs to a toon and only use that toon to do this run, the buffs can last long enough to get at least 5-6 runs done till you have to reapply them. You should only log into this toon when you need to do the orphan run to keep them active as long as you can.
- 50% Karma Bonus from karma boost (Karma Booster, Karma Bonfire, or a Candy Corn Gobbler if you spam it enough)
- 15% from Karmic Enrichment (Purchased from the Laurel Vendor for 10 Laurels) or Koda's Warmth Enrichment (Obtained from the Koda's Blessing achievement), and applied to a Ascended Amulet.
- 5-10% from Guild Karma Banner Boost (10% would obviously be best if you can get one)
- Consuming Candy Canes will give you 10% (Up to 30 minutes)
- 10% from Winter's Blessing consumable (From the daily achievement "Donation Drive". You obtain the first one by giving gifts to 15 Orphans. The boost lasts 1 hour so after the first run, you can have the buff for multiple runs after that.)
- Up to 10% from Guild Karma Boost (From the Tavern in the Guild Hall)
- 20% From Food and Utilities Consumables (All of the Wintersday Consumables has a 10% karma boost on them.)
You should end up with at least 120%-125% Karma boost plus any you have from your Achievement Rewards.
Also, you can also do the Wintersday Jumping Puzzle and the Bell Choir up to 3 times a day each to get around 10,000 karma per run. All together you can get at least 170,000+ karma per day with all of these boosts.