[Suicide Junkie]

Super-Trick with repeat build:
If you are repeat building facilities, and you run out of slots, the repeat facility will be cleared, but the rest of the list will remain.

So, you can give an order to build, say a research facility, and then a Warship. Turn on repeat build at that point, and the planet will be filled with research facilities.
Once the planet is full of facilities, the planet will automatically start building your warships on repeat!

This works on any build queue item in the second slot, not just ships!