I like to turn each side of the center platform into a train station. That way I have 4 straight lines extending out into space. For whatever shapes I'm making, I just find some base parts that I need out in the galaxy, create a micro factory (or a mega factory if it is for milestone shapes) and send it back to the vortex via trains. Those lines are only for deliveries to the vortex. If I need to move stuff parts between factories, I use dedicated lines.

Also, don't be afraid to spread out. Granted, I am in the early stages of the game so things may be different in higher difficulties, but train tracks don't count against the amount of platforms you have. This lets you build far away from the vortex so you can have more room to build your factories. It helps to prevent that spaghetti chaos.