another cheap trick: in late game after unlocking terraforming & Gaia transformation tech, you could turn any colony into a Gaia world apart from a colony on a toxic planet. But if you had a second colony in the system, you could gift your toxic colony to an opponent, then attack it with a stellar converter equipped fleet, fire the stellar converter to destroy the planet and convert it into an asteroid belt, then get your second colony in the system to start an artificial planet construction project to turn the fresh belt into a terraformable barren world.
It's a bit more Douglas Adams than George Lucas: apologies former citizens, you and your corrosive world needs to be vaporised to work around zoning regulations as part of the empire's galactic terraforming project.
Another fun way to play the early/mid game was to try to advance up the tech tree by scrapping captured higher tech ships. You needed large fleets of disposable ships with lots of room for boarding parties, tractor beams to pin enemies, and if possible weapons with radiation damage to kill the enemy crew before boarding. It was particularly fun and frustrating trying to capture ancient-tech antaran ships in the early/mid game (the game designers were wise enough to equip antaran ships with the quantum detonator tech giving them a very high chance to self destruct nuke their ship's drive when you tried to board them)
I used to do a variation of that in Armada 2525. Neutron stars always had very bad planets. I would put a colony there, drop enough work units to build a self destruct, then blow the planet. Artificial planet, now I had a good planet around the neutron star--and every ship built around a neutron star had double defenses. Once I had one such world I used it for as much of my shipbuilding as possible as the ships would almost never be destroyed. I would then go for the other neutron stars, both to increase my building ability and to keep the AI from building such ships. Once I had them all the game was won.
Hmm, I'd only consider that if the planet at the neutron star was either Tiny or mineral-poor; with full tech, even an IRR Small is better than the TER Tiny created by an artificial planet...
But the max you could extend them to was much less. So long as you were doing it for the long term blowing it and replacing it was your better approach.
It's a bit more Douglas Adams than George Lucas: apologies former citizens, you and your corrosive world needs to be vaporised to work around zoning regulations as part of the empire's galactic terraforming project.
Another fun way to play the early/mid game was to try to advance up the tech tree by scrapping captured higher tech ships. You needed large fleets of disposable ships with lots of room for boarding parties, tractor beams to pin enemies, and if possible weapons with radiation damage to kill the enemy crew before boarding. It was particularly fun and frustrating trying to capture ancient-tech antaran ships in the early/mid game (the game designers were wise enough to equip antaran ships with the quantum detonator tech giving them a very high chance to self destruct nuke their ship's drive when you tried to board them)