When do you
 

go and capture another gold mine? I always wait till my other one is like empty then go. But after that I end up with not enough gold to build a new town hall close enough to it. So I end up having to go send miners out to mine then walk them all the way back. lol it sucks. If I can even get that far. lol

You do it as soon as possible, to get more money to get more guys. DUH!!!!!!!!