I'm sure everyone is wise to this tactic, but I have recently discovered the early game blitz strategy.

Basically, earn money on missions (possibly buying a small trade ship if it helps) until you get the ~71k to purchase a Dragon.

By the time it is built, there will probably still be a couple of companies whom own stations but have no combat value on file. Declare war. Capture their stations.

The biggest risk is accidentially destroying their civilian ships. You probably won't have pirate tech yet for captures, so you may need to advance each day manually while piloting your combat ship, so as not to accrue reputation penalties.

Once you do get pirate tech, get some of the smallest cheapest fighters. Put harpoons on one of their gunports, and with only a single erradicator they will be less likely to accidentially destroy ships. Sweep up non-combat ships to build up a cheap trade fleet.

There are probably also still some companies with <30 combat value, this means they have somewhere between 1-3 ships that your dragon should have no problem taking care of. Honestly the Dragon could probably take on stronger companies, since they tend to spread out their forces.

If you declare war on Axis, have some supplies on hand first or you wont be able to repair / refill until you have captured some of their bases.

Buying ships from the big companies should keep you in their good graces, even while your reputation falls with others. If you're willing to risk your combat ship shooting down some freighters, you can leave it to capture stations on its own while you run missions to keep your reputation up -- but the risk of accidental civilian kills is probably a bigger concern than reputation gain from missions.

This is sort of a cheap shot, taking out the little guys. I prefer the merchant play style, but it is fun to experiment with oher modes.