how to earn crrrrooowwwnnssss? D:

Okay! So, this is pretty embarrasing to me, but here goes; How do I farm crowns?
I've never really had to do that, because I spend a lot of real cash in this game... So I was just wondering. It's probably easy, but I honestly have NO IDEA how to farm coins. I only seem to be loosing money, from whatever I do -_-'
So, I do know of, the fsc, the jk runs, all that. I mean, I played since beta. But I don't really see how those runs are going to make me a lot of crowns.
I tried something today, so basically, I joined a jk run from the terminal. Earned 4 k crowns by spending 30 CE on those three dungeons. And atm, 30 CE is like ... 1750 crowns or so.
That's not a lot of crowns, is it now. So, the question is; how do I get more?
Would be veeeery nice if somebody replies, aaand yeah. s:

Arenas.
I've been logging floor crown data for a few days now. Jelly is pretty good, earning you about 20 CE in excess of what you spend on elevators (plus materials and tokens, and remember that 15 jelly gems -> jelly mail -> 3.5k crowns at a vendor). But that's over all three floors. The arena on depth 14 prior to the jelly palace tends to earn 20 CE on its own in excess of the elevator fee. So arenas are far better.
Floors after the terminal are better, as well. Even regular clockworks runs post-terminal tend to make more than 10 CE's worth in crowns. This is doubly true for arenas. Arenas pre-terminal are profitable. Arenas post-terminal are VERY profitable.
If you hit all three arenas on the way down in the current jelly gate you can pick up about 60 CE profit. Do that two or three times in a day and you've made over 10k in crowns of profit (plus you've converted over your mist into something usable). It's much, much slower than buying CE but it's not too bad.
I don't run FSC regularly yet, but from what I understand FSC is the best way to make money, earning 7k crowns for a 5.5k crown profit per run, plus tokens.

When you're trying to figure out your margins, I find it's best to calculate things into cr/CE, and then multiply by 100 to compare my rates with the current market rates for 100 CE.
So, for example, you gained 4000 crowns for 30 CE doing your JK run.
(thinking inside head now)
This rounds to 133.3 cr/CE.
OK, I'm making 13.3k cr/ 100 CE.
I'm making a pretty good profit since CE is 6480 cr/ 100 CE.
(plus tokens/mats)
AUTHOR EDIT: based on my personal numbers, you either did not do D17 and are counting a run from D14-D16, or your figures are somehow incorrect(forgot to include D14's energy cost of 10 CE in the totals, included money gained from tokens/mats in total, or general addition error).
Let's take the FSC example from #1.
Let's take the median of it and say we made 7k on the full run for 80 CE(so not from terminal, but all of T3).
(thinking inside head now)
This rounds to 87.5 cr/CE.
OK, I'm making 8.75k / 100 CE.
I'm still making a profit, but it's not super good. Can I do better? (run from terminal, etc. etc.)
(don't forget tokens/mats)
Both of these examples show that you are still making a profit based on CE spent. So, you could literally play all day doing these particular runs and still come out with positive crowns per energy spent. Even better if you are also using Mist Energy for some of it.
But, does it make a lot of crowns? Well, for the average player, it's pretty good.
If you were expecting to be able to input 100 CE into the Clockworks and come out with some amazing gain like 100k crowns or something, well, I suppose you could be extremely lucky and find something very rare, but usually, it is not the case.
There are, of course, many other ways to make crowns besides running the Clockworks. After all, we capitalists are very inventive about ways of making money. Some minor examples:
-Doing Basil runs and selling recipes
-Using boss tokens to unbind and sell equipment
-UV crafting on alts using Mist Energy
-General AH buy/sell
However, anyone who spends money on the game has an inherent advantage of being able to, effectively, create currency out of thin air(at the cost of IRL currency, of course). This is OK, because it's those helpful people that support the company(OOO) that provides the game(SK), and also support the F2P players with currency(CE) to use.
It is a very interesting dynamic. But never mind that, you wanted to know how to make crowns. I would say that by your example, you are doing mostly the correct thing(s).

Okay, well thank you, for, uhm, telling me all this interesting stuff o:
But would ANYONE be willing to buy.. let's say, a vog cub coat recipe? And doesn't it cost me money to just put it out for auction, and maybe even end up not selling it, and thereby loose money?

While it does cost you a deposit to put something up for sale, that deposit is refunded if you sell the item. If it doesn't sell, then yes, you lose money, I believe. The appropriate thing to do is to put it up at a price where it will sell, but you will still make profit.
(I have heard of some kind of buyout trick, but I do not know what it is yet.)
The AH always takes a 10% cut of the final sale price, however. The best margins are usually to be had(buying OR selling) via word of mouth trading in town or on the forums. This tends to take more effort, and also if you are the kind of person who does not enjoy dealing with people, then the AH is a better option.
Usually recipes are marked up by about 1-2k cr for 3* and 4* recipes(by word of mouth, markups are higher on AH) and by about 2-5k cr for 5* recipes, depending on which one.
"And atm, 30 CE is like ... 1750 crowns or so."
FSC gets you 6-8K (and some Vana tokens) for 80 ce or so. 10 vana kills get you 30 tokens, which means one 5* item you can vendor thrash for 30K Cr. That means one token is 1K Cr. Total vana run is around 9-11K. If you find a good recipes on the way there to resell that can help or even double your profit.
Farming crowns is easier when Ce prices are low, since they're not it's going to be less profitable. That's why people are so afraid of it hitting 7, 8 or 9K per 100, because that's nearing the line where nothing in the game is profitable enough to keep farming indefinitely.