I rarely colonize planets with no minerals; there's little point in my mind. I look at what minerals I'm lacking, and focus my colonizing efforts on planets with them. I especially like systems with sorium-bearing gas giants, so I can set up fuel harvesting operations and drop the fuel off at a nearby colony. Every colony also gets a space port, which helps speed up loading and unloading. For example, right now I have two manned colonies in the Los Angeles system. Los Angeles A-2 is a terrestrial world with decent minerals and a 30% energy weapons ancient construct. So I moved 16 research labs, 100 construction facilities, and 300 mines there. Los Angeles A-4 is a gas giant with a ton of high accessibility sorium and many many moons. I moved several fuel harvesters to it, and have a tanker ferrying fuel to Los Angeles A-2. Los Angeles A-4 Moon 8 has good minerals, especially corundium, so I've moved many mines and construction factories there as well. The benefit to corundium is that I can use it to make more mines. I have mass drivers on LA A-4 Moon 8 sending resources to LA A-2, which also get used on more mines. Periodically, I have a big freighter come and take all the produce to Earth.