Worried about memorizing a fact sheet for your morning meeting? Try sniffing a favorite flower or scented candle first. (Our pick: K. Hall Designs Pomegranate Scented Candle, $19, www.amazon.com.) Smelling a distinct aroma while trying to memorize something, then letting the same smell waft around you as you sleep can boost your recall by a scent-sational 13 percent.