Strategy, hmm..
Contrary to what some people suggest, I like to spend my Scrap early on upgrades and only collect larger amounts if a store is nearby. That way, you get better defenses earlier and conserve more Scrap, and this strategy is self-reinforcing, leading to an all-around better ship later on.
Time your weapon systems well. If your lasers can barely cut it, take shields down with missiles first thing, or the engagement will take 3 times as long (this can be a good or a bad thing, see next paragraph). Make shield-hitters fire simultaneously if the enemy has shields up, make hull hitters fire right afterwards.
The instinct is to take out the shield generator first, but if you can damage their systems and they pose a threat, then you're actually better off taking out the weapons first. Longer engagements, when they're safe, also give your crew more XP.
Juggling energy gives you a combat advantage. Power down the medbay when not needed, pull energy from shields into the engines when a missile hit is imminent. This will allow you to prioritize combat upgrades and invest less in the reactor.
Grab every jump node that you can. Nebulas are actually good because they make the Rebel fleet advance more slowly, allowing you to collect more goodies.
