You know that plant seeder?
Ever wanted to make a custom plant for it to spawn?
Well heres how!

Firstly, Plant a plant, Than, Press tab to enter command mode, Click with the plant selected
Here, you will be shown the plants version of your ship selection screen - Simply hold ALT, click and drag the plant in the ship type slot, Than, stop clicking over one of your empty slots - This will put the plant in your selection, Than, Go into YOUR ship invintory, Click the plant, And edit it however you like! After this, for more plants, simply hold alt and copy the custom plant into another slot - It will keep its command module - this will allow you to create another custom plant!