Just to begin with, i would love it if any other members would be kind enough to post their own expansion tactics here so that we can have a wide array of ideas here for people to pick from.
Flip made a lovely point on another section about rapid expansion vs solid building.
"By rapid expansion, I'm referring to quickly branching out to 4 or 5 colonies while your town levels for those colonies is 12-16.
My thoughts behind this have been a sort of mix between rapidly expanding, yet creating a solid defense for my towns. There's no doubt that this is leaving a bit to rest on luck, luck that you won't be attacked soon, or that you pose enough of a annoyance that would be attackers will look for softer targets.
The idea behind my leaning toward rapid expansion is to locate solid resources and then use those to build *all* of my towns to the highest levels, rather then build up a few solid towns and then move on to the next. Looking at this from a power gaming perspective I'd think that with a moderate investment in 4 or 5 towns depending on what you want... (I went 5) in resources you should be able to then use the newly gained assets to build your empire at a much more alarming rate.
I see a downside to this as well, mainly that all your towns are at a lower level for the short term and that your defence budget can cut into your resource collecting if not properly planned out."