Sarah, I had a similar experience at about age 30. (I'm 33 now.) I have been reading Angie's blog faithfully and improving my understanding of smart casual dressing for my everyday dressing (I'm a SAHM). I have been purging my closet of shapeless, boxy t-shirts and "mom jeans," which have been my uniform for years. I am beginning to make choices of smarter knits or woven tops and dark wash jeans in flattering fits. I also wore clunky white athletic sneakers and white athletic socks with my jeans and tees (this should make you feel good to hear how bad someone else was!). So I am also updating my shoe wardrobe to smarter choices, such as athletic shoes only for sports, flip-flops only for beach, etc. Fashion sneakers and ballet flats are good choices for casual wear. Overall, you're going for a more polished, less uber-casual and trend-ruled look as you go into your 30s.
I would recommend studying Angie's guidelines for the pretty pear:
http://youlookfab.com/2006/04/21/the-pretty-pear/
http://youlookfab.com/2007/08/.....r-in-2007/
so that you can have an idea of what silhouettes and styling are most attractive on your figure. BTW, I would suggest posting a picture of yourself under "body type," in jeans and a fitted top, to verify your body type. I thought I was a pear, but it turns out I'm a flat-chested hourglass with a strong shoulder line.
Try some stores you may not have tried before. Favorites among the YLF crowd are Ann Taylor, Ann Taylor Loft, J. Crew, and Banana Republic.