Shaping Convex hull on a longboard

I am about to start shaping my first board and am replicating an old longboard I have with a rounded convex hull shape to the back half of the board with egg rails. I dont have the opportunity to watch anyone shaping and all the videos I have watch all shape concave on shortboards. Can anyone tell me what the process is for shaping a rounded convex bottom? Presumably you still mow the foam along the rail in to the stringer feathering up toward the stringer?? Or is it all done whilst shaping the rails? Any help would be greatly appreciated.

you still mow the foam along the rail in to the stringer > feathering up toward the stringer,done whilst shaping the > rails. and use a concave sanding block