The engine trails in these actually are not by me - just copy/paste and crop work.
I know how to do them - but I am a lazy bastard. It's a combo of drawing them yourself (the inner white lines, that is), applying outer glow and applying motion blur. Then mask the layer and edit out what you don't want.
The hard part is to get it matching with the FL ships in a convincing way... I mostly use the hue/saturation option to get the part that's on the FL ships matching the new engine colour.