Begin by making a 14 x 18 stud base with flat lego pieces. I made mine two layers thick. I added two 3-inch high supports for the rocket to attach to.
Next I found several round lego pieces that I attached together to make the cylinder part of the rocket. Next I added the rocket boosters to the bottom of the rocket and attached it to the supports with 2 X 2 square pieces.
Then I put the rocket onto the launch pad.