Greyscale, I bought my usual size too and they felt a wee bit squeezy in the gut. They have since loosened but I wouldn't say they stretched a lot. The soft black is really nice but I couldn't resist the blue.

In most Petite clothing, I fall between P2 and P4 which means I am also between PXS and PS. I buy PS in nearly everything knowing it will be large through the shoulders and extra large through the waist. I sometimes buy PXS in Ts and sweaters if the neckline is lowish and the shoulders are cut big. Generally, I like a loose fit and loathe any pull or gaping. I probably tend to buy my jeans too large because I feel that bodycon magnifies the ample size of my legs.

Honestly what Janet said. I think truly sizing up is a privilege of the smaller. For example at my current size sizing up would mean probably XL. Which I'm not doing. When I was significantly heavier I was wearing baggy clothes at a Denny's, I was addressed as sir by the cashier.
Back in the early days of What Not to Wear they'd give example after example of larger women who looked significantly better in fitted clothes.

Anna, I agree - although the randomness of sizing and the number game also contributes. I'm an XL at Forever 21 and a size 10 at H&M but a 26 in Hudson jeans. I sometimes worry that sizing up is what's led to my recent weight gain - nothing to keep me uncomfortable in my clothes.

Forever 21 and h&m I'm probably already at the very top. so exactly how would I size up? That's what I mean.

Yep. And imagine being sized out as a teenage girl - when XL is not even an adult 8 there as far as I can tell.

Sure, since I have an hourglass shape, I tend to go with slightly larger sizes that fit my bust and hips, but I typically buy belted pieces or wear a belt to cinch them at the waist.