My measurements are:
Hips: 45 inches (114.5cm)
Waist: 29 inches (73.5cm)
Bust: 42 inches (106cm)
According to Bravissimo fit guides, this would make me a size 18 at the hips and a size 10 at the waist, which is... tricky. I asked for sizing advice through the online chat and they suggested I order based on my largest measurement. I ended up ignoring this advice and instead ordered the average of my two sizes, a 14 Really/Super Curvy. This is not a knock at the online customer service, it's difficult to make sizing suggestions for someone you can't see, but if you're on the fence about sizing and you're an hourglass, I don't recommend sizing to your largest measurement in this dress. I would have ordered the 18, and it would have been MASSIVE on me. The 14 is still too big. To give you a breakdown and hopefully help others who are unsure about sizing, here's how the 14 fits on my measurements (which I listed above):
Hips: The 14 is a pretty good fit, but the material has enough stretch that I'm quite confident I could have gone down to a 12 and still been reasonably comfortable with my 45 inch hips (although it would be quite "bodycon" at this point, so if you're looking for a looser fit, ignore this).
Waist: The size 14 is way too large for my 29 inch waist. TONS of extra fabric and bunching that I will need to have tailored. I can grab a solid handful of extra fabric at the back.
Bust: The Really/Super Curvy provides just enough of a coverage/cleavage ratio for me in this size and covers my bra (32HH in UK sizes), but like a couple of other reviewers have mentioned, there's some strange gaping under the arms that I will need to have fixed by a tailor. I think this is less a size issue and more of a design flaw. There's also a strange stitch on each side of the bust that makes it lie weirdly that I need to tailor to fix.
Length-wise, I'm 5'10 and this dress hits below my knee. With the ruching, you could probably hike it up a bit if you're short though.