I own two blouses in this style. I like to wear them with pencil skirts or over skinny jeans. They’re very forgiving after a week full of big meals and little exercise. I think because they look intentionally blousy all the time, they can masque a number of sins as long as what you wear them with is fitted.
On a related note, please don’t wear peasant blouses with peasant skirts. It’s a look I’ve seen far too many times. The truth is, you can have too much volume. Unless, of course, you’re talking about hair and then, there can never be too much volume. *wink*