Amazing things can happen with the right foundation wear. Make the dress. If you don't like the resulting look, take a trip to the lingerie department and find a good shaper - but be prepared to spend some cash on a good one. The "wiggle dress" (which is a modern term for the classic pencil or sheath dress) actually comes from an era when no decent woman would go without proper undergarments. I think that's a concept that has unfortunately been lost on today's generation.
Lisa, I think I've got a "wiggle dress." It's very fitted through the bodice and very difficult to zip up. The skirt part tapers at the hips, necessitating the use of shapewear. Also, it's difficult to sit down in it, but I manage.
It's the kind of dress I wear to be dressed up, and never any other time.
Oh, by the way, Ladyface, I'm sort of a pear shape.
Two things would help, I think--Extend the shoulder slightly in order to balance the top with the hip ,and in the skirt area taper downwards so the circumference is less at the bottom than at the hip by quite a bit (baste first). then leave 3 or 4" slits in the side seams so you can walk and sit with comfort. I've been making a lot of my own clothes since the forties. I've also designed successfuly professionally. You can do this, good luck!