While the compulsaries are very important (yes yes we all know my story) aslong as you can hit one, you get to fs. So if you can't do all of them its not the end of the world, but make sure you can do atleast one, or it will be devistating. Trust me...
As for making a FS, im the wrong guy to talk to. I just yoyo to the music alot for the weeks before it and get a feel. Try and find a few tricks that your comfy with that flow together well and just give it a go. If you have a video camera it can help to, because then you can look back.
Another tip, be yourself. It makes for the best FS ever. Dont be nervous, we are all players, and noone will laugh of make fun at you. If they do, they will be receiving a large helping of butt wooping from yours truely.