Ex: Loft

Solid

Create 3 circles for the profile

Radius: 400, 150, 300
Height: 250, 500

Home tab > Modeling panel > Loft

Select circle from bottom to top

The solid is form after click on the last circle

Press Enter

Press Enter again to confirm the Cross Section only option

Surface

Create 3 arcs for the profile

Radius: 300, 150, 300
Height: 250, 500

Home tab > Modeling panel > Loft

Select arcs from bottom to top

The surface is form after click on the last arc

Press Enter

Press Enter again to accept the Cross Section only option

Edit Loft Object

Select the loft solid or Surface

By default is Draft Angle option

Ruled

Smooth Fit

Normal to All Sections

Normal to Start Section

Normal to End Section

Normal to Start and End Sections

Loft by Guide

Create 2 stars: Radius 145, 95

Height: 450

Home tab > Modeling panel > Loft

Select the star from bottom to top

Press Enter

Select Guide option

Select the guide lines

Press Enter

Loft by Path

Create 2 circles: R100, R300 with a spline in Z axis

Home tab > Modeling panel > Loft

Select circles from bottom to top

Press Enter

Select the Path option

Select the path