If almost but not yet crippled, RUN AWAY. Warp out, survive.
If crippled, hide behind some terrain and hope your side wins.
If your shields are down its worth switching to boost shields for the 20+/30+ ships for a turn while moving away to preserve those valuable ships hulls.
The game is destructive and bloody, ships exploding or being wrecked all over the place. If you lose a battle then you have lost any ship on the board that cannot warp out.
Campaigns are going to be bloody affairs since losses will be high. Those 2000 point campaign fleets can be cut in half by a single battle meaning a single battle can leave you far behind.
Hull damage is hard to avoid but if at all possible you should avoid it. A few turns will restore your shields, nothing during the battle can restore your hull.
Which is also why you need to shoot and KILL enemy ships not just damage them to stop them running off and boosting their shields :twisted: