Well, not too sure if there really are too many places to efficiently farm things.
If we start off with dailies then they are only really efficient at farming exactly that thing. If you ONLY and ONLY want that specific thing and nothing else. But in general that is quite horrible since you'll miss out on a lot of other things. If you farm the gold daily you will miss out on seeds and possible manyus. If you farm manyu dailies you'll miss out on gold and seeds, plus you will only get 2 types of manyus for each daily.
There's in general a huge debate between 12-3, 2-1 and 1-3.
If we go by purely wanting exp fodders and gold, then 1-3 will be your best bet as the gold from selling girls will come out even with 2-1.
However, 2-1 does give more seeds while still being on the exact same exp efficiency as the 12 stamina bonus stage, which makes it a favourite for many. 2-1 and 1-3 are thus the best bets for anyone that is still leveling unevolved characters.
Once evolved characters start getting into the picture, however, 12-3 and the 80 stamina bonus stage will outshine the other two purely out of the insane gold costs and amounts of exp needed to level high level evolved characters.
The whole 12th area is also the only "reliable" source for ampys, with no other area offering them. If you want to go for getting as many ampys as possible, then 12-1 will be your lowest cost stage but at the same time being less exp efficient than the others.
12-3 and 12-5 will be your best all-round choices with 12-3 offering a good amount of exp and also still offering good money and seeds. If you place your characters correctly the RNG for getting the chests is also very small compared to 12-4 which is a horrible RNG fest of doom and destruction. 12-3 also gives the most money out of 12-1 to 12-4.
12-5, if you can complete it reliably, will be your best bet for all-round everything later on. It has the best exp per stamina, the most gold per stamina, the most seeds per stamina and can give both ampys and 80 stamina gardens as well as having good RNG for chests if placed correctly. As said, if you purely want ampys, you will want to go with 12-1 or 12-3 instead as they are cheaper while providing little RNG.