I love tunic dresses like this one, with an elastic waist. They’re so flattering and comfortable! Often they are called “pop-over” or “blouson” dresses because the fabric blouses out over the elastic, which creates a flattering silhouette.
In this plus size casual outfit, I added a colorful clutch (the color pops because it is opposite of the yellow on the color wheel, see this post for more ways to use color theory when styling outfits), chunky sandals, and a denim jacket. Simple, yet interesting.