Modeling Curved Surfaces

Hello there,
I have been going back and forth, for the past year, with trying to make a ship from the Star Trek universe. Everytime I learn something new, I come back to my abandoned project and apply the new techniques. One thing I haven’t been able to get my head around, is how to handle the curves in the image below.

Should I be creating the top oval shape first and finishing it. Then creating the bottom and simply moving it into position? Or should this all be one piece? If I try to do curves by hand, they never look good and if I try to stretch/skew/edit a sphere, it does look better but it still doesn’t feel right. Or should I just be outlining the whole thing with a vertex/extrude and then edge select/extrude to fill it in?

I don’t know. I feel like I am missing some fundamental understanding of ship design. Can anyone comment on how they would tackle a project like this? Specifically the general shape of the hull.

Thank You

What about an evenly subdivided sphere and some proportional edit?

Of course for perfect shapes you need math…

If I were doing it I would start the curved shape first with as little geometry as needed so when it gets to the nacelle section you don’t end up with a super dense section of mesh. From there you will be able to add in the geometry as needed to smooth everything out. Had a similar problem when I first started and tried the ncc1701-D.