How big you are is relative to the size of the world. I'm in world #14, which is maxxed out at 1322 players, I'm ranked 76 right now. Moving up from bottom to the lower 100's is easy, but just about everyone above me has more than twice my value flying way more passengers. Its only going to get tougher from here, but it's a fun game.
A few things I and a few friends are doing...
I look at other airlines, what planes they're using and what routes they use them on. I know I'm not the best mogul'er in the world, and have learned a lot from seeing other routes
Once night I had enough cash to finally go trans atlantic and managed to secure the last remaining gate at London Gatwick. The (used) 707 I was eyeing suddenly dissapeared from the used market (it was a rare 'below value' sale..) so I leased a 707 until I could buy a Convair 990, which I'm finally about to replace with my first 747. Don't be afraid to lease but keep it short term. I try not to lease for more than 2-3 months at a time.
Keep the planes full, I try to stay in the 90% range but the more routes you get, the harder it is to do so.
Excel your routes. When I was first starting I would log each route into an Excel spreadsheet with formulas to calculate the cost, proftability, and seat revenue per mile for each route and aircraft. There's too many routes to do so now, but with a smaller airline it's not a bad idea. I turned many $40k-$60k routes into $100k routes doing this.
Thats all I can think of off the top of my head. Just have fun with it and don't be scared to fly into the big cities, just think twice before creating a base at one.
