Two staples that work in every season are the maxi skirt and the maxi dress. They are both modest and can be dressed up or worn casually.
Of course, the modesty statement is only really true if the fabric is a high quality, thicker fabric, or if the garments are lined. So, I choose wisely and carefully because I very much dislike wearing a slip.
The above skirts are my favorite of the season because they are carefree and lined. They work with a tee shirt or with a nice summer sweater.
About a year ago, I received the red maxi dress (shown above). While it doesn't fit me now, back then it was like wearing a breath of fresh air. So light. So cool. Plus, it had pockets.
Also last year, I received the above pink color maxi. I had to layer with a layering tee so that it would be modest. However, I wasn't fond of how thin the fabric was, so it was not a keeper.
I have also really enjoyed my LuLaRoe maxi skirts (purchased from Poshmark). They have a thin outer layer, plus an under layer that is thicker. They are not heavy, and feel quite silky and soft. I love the designs on these.
Overall, maxi skirts and maxi dresses are a hit. Again, just be careful that the silhouette fits your body type, and that the material is high quality.