I agree with Gre Magus to some extent. Manufactoring, Tech, and Economic Capitols should be specialized ( Political Capitol too if you bother). And the economic starbases around both tech and manufacturing capitols are helpful.
Other than that I like a few more high and mid production planets -- usually planets that have bonus tiles on them. I only put labs on bonus tiles.
Other than that, I like 3 or 4 manufactoring buildings per planet, a starbase on all planets ( usually buy it when I colonize it ), 2 farms producing 6 food each per planet to get max pop up to 17B, rest of tiles I fill up with markets and upgrade to stock markets.
However specializing more planets in manufactoring or research that are in the area of influence from economic starbases you build around your high production/research planets is an option. Personally, I'm usually too busy conquering to build up that much.