Choosing where to start
Select a continent
a) North America: North America holds 6 out of 10 the worlds busiest airports, and a stunning 28 airports with annual passengers over 20 million. Difficulty Level:9/10
b) Central America: Departing from Central America, most the the important routes are within the range of a 737, and with smaller airports and less of them, means less competition from within the continent. Difficulty Level:5/10
c) South America: as a beginner, this could be your place to test out the game, and learn more about it. South America holds 399 airports, though most of them being tiny ones. Competition here in minimum.Difficulty Level:3/10
d) Europe: Europe has many large airports, and, very close to each other, while this means good profit, it also means extremely tough competition. Most of the time, within the first 1-2 years, the larger airports in Europe are always out of gates.(It doesn't get any better later on) Difficulty Level:10/10
e)Africa: Very much like Central America, the northern African airports are capable of transporting passengers to most of the European airports with a 737, though itself doesn't have any exceptional airports, this could be the place to avoid competition and yet still be able to access the European market. Difficulty Level:4/10
f)Middle East: As is has always been for the past one thousand years, the Middle East is the gateway to Asia, from Europe, or the other way around. While consisting of a couple of decent size airports, it is also capable of flying to different destinations in Europe and Asia.(This is critical in the 50's era, since it hasn't yet entered jet age) Difficulty Level:6/10
g)Asia: Asia is the wierd one, at least for the time being. With a massive Asian population in AM, Asia seems overly crowded. With major airports distanced far away from each other, and heavy competition; Asia, like Europe and North America, might not be the place a new player wants to start in. Difficulty Level:9/10
h)Australiasia: With large airports likes Sydney, Melbourne, Australiasia is an decent place to start out in. The negative side to starting in Australiasia would be that long hual flights to Europe and North America just isn't possible(except the 2000 era). Difficulty Level:6/10
Select a hub
The following should be noted while choosing a specific airport to create your hub in:
a) If you are planning to aim high, a high traffic volume airport can not be neglected; yet, if you are only playing for fun, and do not want to spends hours editing your routes everyday, then a smaller airport is suggested.
b) Location of your hub: An airport located near the center of your continent would be the best choice, since you would be able to fly everywhere with a single type of aircraft, thus making your fleet management easier
c) Do a little research before you choose your hub. For example, Hong Kong is the most crowded airport in Asia, not because of its location, nor of its passenger volume, but because of the Hong Kong population actually playing this game.
More hubs
a) The secondary hubs should be located closer to your primary one, since that way, flights could be created from both hubs to one airport, thus lowering your expense on gate rental.
b) As for the other hubs, distance to your primary hub shouldn't be the only factor. Other factors such as the distance to another continent, or the competition within the airport are also primary factors.
Choosing your fleet
In the early stage
The following factors are the reasons why I personally would choose one plane over another.
a) Cheap
b) The size of the plane isn't a consideration in the early stage
c) The range of the plane(The longer the better)
When competition starts
When competition starts to get brutal, these are the following things you would need to consider
a) Calculate the maximum amount of passenger an aircraft can carry in 24 hours, relevant to the range. Do a calculation of 1000nm, 2000nm, 3000nm, 4000nm. This way you could determine in the specified range, which specific aircraft could carry the most amount of passenger. Use it.
b) When competitors lowers their price, don't simply lower yours too. Increase the frequency of your flight. This way you could be making the same amount(almost the same) of money while matching your competitor's price.
c) Refresh your routes before lowering your price, cuz somethings a little "update" could turn a route with 0% to 100%.
Long-Hual
When I'm talking about long-hual, I'm talking about flights over 4000nm. Choose the fastest plane with the highest amount of seats. For example, in the 2000 era, 774 could do round trips in some routes where the 773 could only do one way. That means more passenger, thus lower price, better stand in the competition.
Will keep updating later... bored of typing