When I was a size 8/10 I went shopping for holiday clothes and bought this lovely dress thinking it was a size 12, and it fitted like a dream, it was slightly loose, but in Morocco that IS the dream part... it was a size 22.
And recently I bought another New Look dress that was a size 20, and almost too small on my bust.. I'm a 12 (normally), so I'd hate to think about what this dress would have actually looked like on a size 20!
I have the problem with my body of having too great a variation in my measurements: 40: 25 :38, that's three different sizes + I have thighs that fit into a size bigger than my hips!