At game start build a fast colony ship to use as a population shuttle. No need for life support because you will only use it to go between your planets. Build and launch your “real” colony ship, MAX it out on population, which you typically can’t do without running your home world dry. I built a double and take 6 to my new planet > Bang prolific=12 on planet. Now take your trailing people bus into orbit on the new planet and eject. Take 6 back to the home world…. rinse and repeat. Approval is an issue early on but who cares.
Another tick I do (probably known to all you pros) is to build an empty hull in designer. Shipyard really can crank these out at 3-4x compared to even your cheapest colony ship. Then take one turn to upgrade it for 300-500bc depending on the colony ship configuration you want/need. With the games 5000bc to start it can give you an edge in the early rush.