1. Onia Sienna Swimsuit ($150) A year ago, the one-strap was a trend; now it's entering staple territory. Onia's nylon-spandex suit creates a flattering silhouette with its two-tone color blocking and cutout back. Available in five colorways. Buy it at Amazon. 2. Moscot Originals Lemtosh Sunglasses ($290) "Transparent frames have never looked better," said Justin Fenner at Men's Journal — thanks to brands going see-through on classic eyeglass shapes.