Tip: Have a special fleet designed with the intent of fighting Urgans (if you focus is on fighter combat).
This fleet should be focused on tanking damage while throwing as much damage as possible right back at them, long range weapons should do the trick.
Tip Late game, the best use for 3x3 Turrents is Missiles &/or Torpedoes. It doesn't consume as much energy and can provide nasty close-range firepower (missiles) or additionally long-range firepower (torpedoes, especially late-game)
Tip: The 'Excessive Missile Barrage' option can, in an emergency, be used to to 'shotgun' enemy fighters. This is especially effective when enemy fighters are in range of multiple ships, the only caveat is you'll have to target individual fighters. Over and over.
Tip: Diplomacy is a bit unbalanced, abuse it!
Tip: Human Corvettes suck, but their Cruisers are not to be taken lightly...
Tip: Planets with no resources make decent Military Industrial Centers, especially at the edge of your territory.
Tip: A well-designed ship is worth much more then any Military Sattelite, a ship can manage to stay just out of enemy range (and possibly continue to fire at them).
Tip: Galaxy Arms are easier to defend, need less resources to defend, and give you the ability to build up ships out of the sight of your opponent should certain treaties come into play.
Tip: Keeping one Pirate Planet 'alive' gives you an excuse to diplomatically raise the respect of other nations.
Any one else got some tips?
Edits for making it look nicer.