Composition of your fleet

As you level up and earn battle points you unlock some new ships and most are left wondering what is the best composition for there fleet is. From my previous experiences the most important thing to win battles in Fleet command is the state of your crew and not the composition of your fleet. From my experience a fleet with 5 Dreadnoughts and 5 Aircraft carriers cannot match a fleet with 10 Dreadnoughts. Simply put pack your fleet with the most expensive ships ( Dreadnoughts ) and you have a good chance of winning most battles.
Having said that you can't pack your fleets with Dreadnought early in the game so what should the composition of your fleet look in the beginning ? , I will share what I did and I believe it helped me level up quickly. What I did was as soon as I had enough battle points to buy a ship I bought it. After my fleet was full I sold a cheaper shop and bought a new one and so on and so forth until my fleet was filled with Dreadnoughts. I never sold a ship until I had enough to buy a better ship.
Know of a better way to handle your fleet ? Please feel free to share it in the comments section.