Whether at home in Russia or traveling, Dementieva counts on these essentials. * Hamilton Quadblock Milk SPF 30+ ($13; chemistdirect.com) This sunblock has a lot of staying power-it lasts through three sets, no matter how much I sweat. * Prana Tech raglan top ($48; prana.com) I wear comfy clothes like this top and a pair of simple black yoga pants when I practice. * Maybelline New York Colossal Volum' Express Mascara ($7; at drugstores) This is the one beauty product I always use because my eyelashes are nearly invisible without it. * Yonex SHT-304R shoes ($70; tenniswarehouse.com) I have a pair of these sneakers that were custom-made for me.