grinding? golden lotus + IoT dailys = 50 charms and takes less than an hour..
I'll have to agree with kittycovox. This is what I have been doing since I stopped doing dailies for rep. Another idea is to just do the Golden Lotus quest at the Goldne Pagoda once a day for five days.
I just randomly fly myself to ToT each raid and check the Vale rares and a few dread waste rares that are on the way. I normally get 3-4 per day and thats 10-16 coins. It's a way to get them without sitting there and doing something in a chunk of time which I kind of like.
Oh boy this thing needs some fixing in next expansion... for being most boring thing implemented, but not in vain (me having too many characters). Like why cant over the cap elders turn into lesser ones.
For me the most efficient way in 1 day would be running the isle dailies (30 + key from chest for some elders) maybe do the weekly quest at barrens commander killing(1-2 per kill) + some pet battles if needed.
Did just pet battles for awhile (pve), but the drop rates have been just awfull recently (lvl 24-25) with streaks upto 20 battles with no charms.
It depends on my mood. Lately I've just been grinding Commander kills for the Barrens weekly, and it gives a fair number of charms per kill. Also, I think you only need to do like 2 days of IoT dailies per week to get enough now.