Racial Traits

[Hotfoot]

If you can manage it:

Advanced Storage Techniques + Hardy Industrialists + Natural Merchants + High maintenance trait + (optional) Temporal Technology + (optional) high reproduction/tolerance

For added effect, choose gas as your planet type. Your larger worlds will be capable of insane rates of production (and just imagine ring and sphere worlds), and you can get instant benefits from your colony worlds. With reduced maintenance, you can maintain larger fleets than your enemies.