1) always do the combat by yourself, don't rely on auto resolve.
2) Try to get the tartans(then broadsides) with your bigger ships first, they kill bombers too fast.
3) Try to bring the fight AWAY from the spacestation. Concentrate your firepower on one ISD first, then another, then rush the station.
4) Aim for the hardpoints. Kill the hanger first, yoou can do that with all the bombers at a ship first, use your special ability. Use fighters to protect bombers.