fighters can be somewhat useful for taking out Marauders or Broadsides since those ships are horrendously slow.
as for using tactics for your fighters and bombers, first, you have to remember that fighters and bombers are really cheap. in other words, you don't necessarily have to protect them at all costs. second, remember that if one ship is occupied with your fighters, that leaves room open for your bombers. using several fighter squadrons to harass the corvettes and keep them occupied keeps things open for your bombers. a simple tactic that i've used several times is the Ion attack ability from the Y-wings to better enable the fighters to harrass corvettes.
another possibility for fighters is to throw them at corvettes which leaves your capital ships open to attack the corvettes, even with low health or sheilds. fighters do have their uses if you use them properly in the first place.
See the struggle of the faithless lot as they negate their time
How low to sink to the depths of their frame of mind