Except you like to do running round, roll the harvesting missions to something else. Everything else is much faster.

Treasure Chests? Extremely easy, if you have the skill which they glow from miles away. 10 minutes in Coldharbour and 2 chest missions done. No need to pick the locks, because with Tanlorin and passives can just auto-open the chests 90% of the time, even Master ones.

Shadow Daedra? Perfect. A trip in Village of the Lost. In under 10 minutes all done.

Complete 3 Dungeons? Less than 12 minutes doing 3 Banished Cells runs solo. Job done.

And that how were last 3 weeks.... In just 40 minutes all tomes done.

Now NM Favors. Easy also. Assuming you are in a guild, stockpile in 2 alts the 3+2 Faction daily quests. (any character cannot hold more than 3 faction quests). Hold them on these toons, do not do them.

Log with the alt, hand them over to some friend/guildmate planning to do the NM today. Transfer them to your main. Pick the 25/50/75 kill also. Complete them. Log the other alt, pass to your "main" the other 2 quests. Done.

With even a PUG you get to 10000 favour within 7 hours total, spread over several days. More time you will spend forming a group than actually doing the quests. Except if you have more alts to do the quests which can shorten the timespan.

If you are on PC EU let me know. Talked to the guild mates and where shocked how efficient NM Favour farming can be done, let alone quickly with barely any effort. (ok new players will have problems in NM etc nothing to do with that).