When I get writers block (it happens, even to me), I usually step away and do something else, something not computer related. Read a book, watch TV, play with my pets, ect.
If I have trouble coming up with ideas (very, very rare), I find that giving myself limits helps. So I'll give you an idea for one:
The ship can be no bigger than 600 meters, and can't have any beams or flak cannons. It should be of Terran design. No fighter bays.
There, try playing with that. Maybe something great will come to you.
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Warpstorm. Do it now.
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I know there is a method, but all I see is madness.