The problem with starbases - for me - is that I just can't be bothered to send countless constructors off to build the things. I know it's not really difficult but if you want to build even a few starbases then it just gets a bit repetitive to have to direct constructors every turn or every few turns.
Therefore my suggestion is to enable some sort of onsite upgrade for starbases. To add an options menu to starbases that allows action without using constructors - after the initial constructor founds a starbase. I don't think this idea is unrealistic either, I think if starbases actually did exist then they would have to be in some way self sufficient e.g., a proposed moon base might have to extract life support from moon rocks. I'll ignore the obvious counter argument!
Please post comments and I welcome others' suggestions for onsite upgrades to starbases that would perhaps add even more fun and ingenuity to the starbase concept!