This has been asked a few times and it’s one of those things that on the face of it sounds really easy.
Humm, so where to start???
I have had a few goes at these using lofts, extrusions with guide curves, sheet metal loft in an assembly (4 or 6 parts welded together) etc… but nothing really looks correct with the methods I used.
Ok, back to basics looking though my surfacing tutorials from time gone by. The good old Boundary Patch tool along with a guide surface for tangency seems to give the best results so far. I have been stuck in the “solid model methodology rut” when surfacing really is the quickest and easiest method. I think I will spend a bit of time re-learning the advantages of hybrid surface/sold modelling.
I hope this is of use to someone
Merry Christmas to all