Most people use a fairly standard start from Earth, this thread is for thinking up interesting alternatives to that.
One thing that came to mind in the Ark Ship start. You start with a large number of full colony ships and cargo ships laden with infrastructure, terraforming installations, factories, automated mines, a few mass drivers etc, a few maintenance ships, asteroid miners and some terraformers. In a system with 2 or more reasonably terraformable worlds. Total population would be maybe 400 million. This would be a very different, and possibly considerably harder start then normal, but it could make for an original storyline.