1. When you can, get a second layer of shields. Shields are good; shields are your best friend. More investment in shields early on protects you from enemy weapons, which in turn protects your hull and prevents accumulating hull repair costs.
2. Generally, buying crew from stores is a bad idea. Plenty of events pop up throughout the game which give you crew for free.
3. By the end of the game, you need at least level four shields and either a teleporter or cloaking device. The flagship has a nasty missile weapon to tear your ship apart.
I hope this helps somebody. It took me a long time until I realized the importance of early shields, so don't feel bad if you don't get it right away. Have a good day!
