cressetmama, you are lovely! I'm not a style guru. I used to work in the City, now I work for an engineering company.
Dancergirl, I love colour - but limited to an item (just like the prints). One of my favourite cashmere jumpers is a Ralph Lauren one bought a Bicester in orange.
Regarding wearing shirts under jumpers, I loved the suggestion above, but what I tend to do is buy a bigger size, then get it tailored.
This means it will fit you in the boob area so no unattractive chest gaping. It also means the shirts tend to be slightly longer so they don't ride up and can be tucked into jeans comfortably etc
I know this thread is about looking expensive, but what I believe the title is referring to, is how to be stylish in any clothes.
One last photo of me (was asking DH's advice - no idea why, must have been feeling v insecure that day).
This is a M&S dress with a CH Carolina Herrera jacket. I spend all my money (in the sales) on decent out wear, shoes and handbags.
As you can also see, as the outfit was so neutral I stuck my skin lift red lipstick on.