The first thing to ban from your wardrobe when you get ready to go for your run or walk/run: Your trusty cotton tee. "Cotton is one of the worst things you can wear, especially if you are training outside, because it holds moisture and can make you feel cold or clammy and uncomfortable.
Instead, choose clothing made from moisture-wicking fabrics, such as CoolMax or DriFit, which will pull the sweat away from your skin. That includes your socks as well. "You'll have less moisture, heat, and friction around your foot, which means fewer blisters.
Dress in layers, especially when the weather is cool. "You'll want to dress as if it were really 10 to 20 degrees warmer outside, since your body will heat up quickly," adds Solkin. Wear a light, windproof jacket out the door (and a vest if it is very cold), then tie it around your waist when you heat up.
Finally, don't forget one very other important piece of equipment: a supportive sports bra. Whether you're big, small, or somewhere in between, keep the bounce factor to a minimum by choosing a model that fits you well -- larger-chested women may want to try an encapsulated model, which separates the breasts. Don't be afraid to bounce around in the dressing room to see what works.