OP I'm the same size as you and an hourglass shape with heavy bottom and very sexy, stumpy legs! So I have recently made the decision to give up on trousers as they were never really flattering. I read an article with Kirstie Allsop who pretty much has the same body as me, but less chubby, and she said she too never wears trousers and goes for lots of dresses cinched at the waist. Hear, hear!
I invest in lots of good quality dresses, always with a waist and from places like Jaeger, Hobbs and sometime Monsoon to ensure good quality because cheap stuff just doesnt work as one gets older - firm fabrics required! Avoid Primark, New Look etc! Then I invest in loads of M&S tights in black, navy, green and some good pumps and boots. A few thick belts in brown and black and voila - a daily uniform.
Weekends I tend to go for the same but more casual, eg. dresses or long tunics from the White Company which last well and are very flattering and good quality leggings!
Now that I'm past 40 I try to spend more on shoes, scarves and good jackets as well as bags. Makes all the difference in the world.
I've also found that muted colours are best rather than buying brights or too many patterns. Stick to neutral clothes and then use scarves for colour if desired. My body is just too big to cope with loads of pattern!
Reading this back it sounds a bit smug but not meant to. It's a bit hit and miss to determine what works, but I've come to the conclusion that: quality neutrals is the way to go and 'less is more'.