Ok, cool, i was gonna do one of them myself after i finish poseidon. First thing i would do is look at real floorless coasters, like
Scream and
Medusa. Notice the elements they have and the way they flow from one element into the other. Then, start thinking. You want a fast-paced fun coaster. But you dont want it exactly like Scream or Medusa so you have to do something different. I would think of the drop, do you want it as a drop, and if so, what *(degree) of ncline do you want. If you want like a helix drop, like on WWS's
Mechanic, then you gotta think how big, how much banking and how wide. After that, you gotta think, what would be the best element do you want after the drop/turn. If it is a drop, then you might want a loop or a seaserpent or some other inversion that inclines. If it is a helix, i recommend a corkscrew or something that doesnt incline too much. Then, you have to think, i got the first element after the drop done, now what would be cool. Maybe another inversion or a high -g hill. Or maybe a tight-high-banked helix would be cool. You keep doing that until you are done.