We do milions in hour, but not over "short period of time". We just play a lot, searching for opportunities and we worked hard for tools that allow us to use those.
Trading is the best way to make money and you can earn a lot relatively quickly. Even at start, Hauler can get you a 250k profit, transporting rares. Now, if you want to hear: go to this system, buy this commodity and so on, you will not get that from me. If youre too lazy to figure it by yourself by reading hundreds of topics about this, then you just dont deserve to earn. Period.
So, a Hauler can get you a Type 6 in no time. This ship can haul as much as 112 tons of cargo. Most common routes (as get Consumer Tech from High Tech system to high population agricultural system, earn 800 credits per ton, get tobacco back, earn 600 credits) will give you over 150k each round trip. And its quite possible to get routes that give you twice that much.
Having a Type 6 makes it possible to earn other ships relatively quickly. I got full A grade Eagle, full A grade Type 6 and almost A grade ASP.
I use the eagle for fun, not making money. The ASP is fitted with Advanced Discovery Scanner and Detailed Surface Scanner- i used to use it for mining, but i find it boring. So now i use ASP to fly around an area i like, gather the trading info (visiting stations, taking notes about the commodity prices), doing missions for reputation and fun, and exploring the systems unknown to me (best exploration profit so far: 128,000 credits).
Now i know all the systems in 30 ly around the place i have chosen for a home. I know where to transport a cheap commodity to the place they need it most. I fly around in an ASP, doing missions and exploring, while still having 72 cargo space. I get a mission for system next door- i see that i can earn 500 credits hauling Silver there- i earn 36.000 just by the way. Also, i like to hang in the Anarchy systems Nav Beacons in the ASP- last time i got over 800.000 in bounties and gathered cargo for another 250.000.
Now, that makes me feel pretty safe and allows me to set other goals than making money: currently we are planning to create an Empire Aid convoy, which will transport weapons, medicines and slaves (to annoy Federation peasants) as a gift to brave Lugh Crimson State rebels.
Oh, and about cashing an opportunity: yesterday the trade fixing attempt caused an "Imperial Slaves glitch", which caused the Imperial Slaves price to rise even up to 16.000 credits. It dropped down after you sold any Slaves at the price, but most of the stations with IS demand had it. So, the trick was to buy those at 11.000 credits and go find stations with the huge price. I made 8 milions yesterday.
So, the way to go is to work for the freedom. You cant expect someone to take your hand and lead you to profit, you have to find your own way. But its really easy, just needs some time and involvement. Believe me, it is fun and rush of blood, when you find a five stations trade route, when every jump gives you above average profit. You just need work for that...