Fleet Planning (the Thalstan Method)
First, decide what you want to do in the game. Bounty Hunter, Escort fighter, long range bomber, trader, miner, salvager, passenger transport, providing transport to org mates small industrial ships, providing a base of operations for org mates, whatever. You can have more than one thing you want to do, but you should identify all the ones you want based on your experiences
After that, figure out which ships would benefit those professions. You might also want to consider which ship you will progress your play with.
Then, get those ships.
For instance, you are interested in mining and you plan on just mining solo. You also have an interest in hauling your goods from your current refining location to a market.
For this, I would get a prospector and a freelancer or freelancer max. If you want longer range, get a MSR or a Aquila. Any other ships you get are extra.
After talking to a lot of people who have backed with a lot of ship, I have found that most people will only every use 5 ships on a regular basis, no matter how many ships they have. They have another 5 or so they will pull out on special occasions. People with excess of 10 ships usually say that those extra ships are hangar queens that pretty much got taken out for a few spins when they went live, and then are never touched again...