As I mentioned Saturday, I saw lots of denim and chambray shirts in Paris - they were worn in an amazing variety of ways...
Most simple is wearing these shirts with black. This can be a nice relaxed "out for the afternoon" outfits with pants and flats, or much dressier, with a pretty skirt and clutch bag. Sleeves can be rolled, collar stood up in back - anything that personalizes your shirt and makes you happy!
FWIW, I noticed when I was doing these links that House of Fraser is currently offering free shipping to the US through at least the 13th of October. For those of us who've been skittish about ordering from another country, this might change everything!
A collarless chambray shirt can be a nice counterpoint to a dressy skirt. Where something lacy or floral might go WAAAAY over the top, these outfits look like you mean to be dressy, but you're not getting carried away. (and look - NO POCKETS!!!)
A faded denim shirt is an excellent way to break up an otherwise conservative workday outfit - perfect for Casual Fridays in a "not REALLY casual" office. (this shirt is also available in a darker denim)
I saw someone wearing a denim shirt UNDER a plain black dress (make sure you've got room to do this - no sausage stuffing allowed!), and then 2 days later, when it was warm, I saw a denim shirt partly buttoned and belted over a floral dress. That's imagination!