QUOTE(Kyl3 @ Oct 6 2008, 12:15 PM)
Tried this few days back but not sure I sucked at it or what, can't really generate much income.

And my railways all 1 track only
Check the 'Cargo Payment Rates' by clicking and holding on the Graph icon. This will show you payments rates in days in transit(in days of 20's).
Passengers have the lowest value, and their paying rates
degrades over long travels, like 20 days or more. But passengers are good because large cities have more than an abundance of supply of passengers as opposed to regular cargoes.
Stuff like coal can take a longer time to travel without degrading much of its value. And it's one of the higher paid cargoes in the game, close to goods/foods and valuables.
Realism can be much applied here, for example goods (let's say 3D card la as the cargo), while you take 6 months to bring it down to a city, the value of the cargo has degraded why? You guessed it, the 3d card also obsolete by the time it reaches there

Even the loading of the cargo FROM the station to the TRAIN (y'know when the % goes up and down when picking up/dropping goods) also affects the days in transit, so don't have overly-long trains for industries that produce very low goods(e.g. 38 Tons of Coal Produced Last Month

That's about only enough for a train with 3 cargoes/van long!).
Send things far, send things fast. But do keep in mind of the payment rates in transit

My friend once did a mammoth-train(like 20 cars long), carrying like 600+ passengers for 6 months plus across the map(another 6 months just WAITING for them to fill the train), but only earned 20'000 because of the long travel