Right about now, the summer love of sandals is wearing thin. Catch me on the wrong shoe day, and I'd gladly trade the blisters, aching arches and stiff toes caused by strappy sandals or flip-flops for a cushiony pair of flat boots and the thickest pair of black tights you can find. I was ready to forgo fashion for comfort until I discovered Apara's Gel Slingies, a pair of adhesive gel insoles that can be used in almost any shoe, including those that have an open heel (no ankle or heel straps). The backing was tough to pull off the sticky insert, but once the gel pad was firmly in my shoe, my sandal-weary soles were sighing in relief. The three-quarter length insole fits from the base of your heel to the ball of your foot. $9.99; various retail locations, www.aparafoot care.com.