2 min read A GREAT PAIR of underwear won’t get nearly as much attention as a new watch or a fresh pair of sneakers, but it’s arguably the most important piece of clothing you put on every morning. But I’ve found that once I discover a pair I actually love, stocking up can get expensive. As someone who spends a good chunk of the year testing underwear and covering sales, I can tell you Prime Day remains one of the best time to stock up on essentials. And since it’s the only Prime Day sale of the summer, now’s your opportunity to refresh your top drawer. SHOP CALVIN KLEIN UNDERWEAR DEALS If I were you, I’d prioritize deals from Calvin Klein, a brand that’s remained an underwear heavyweight for decades. I’ve worn all kinds of styles from the OG label including boxers , boxer briefs , and trunks. The fabrics are soft, the fits are dependable, and the designs are timeless enough that they never feel dated.…