You can use this technique outdoors (if you have the option) or indoors. The advantage of setting up indoors is that you have more control over the lighting and there's less risk of a breeze disturbing the water droplets. You also don't have to get up early to shoot the morning dew!
In addition to a macro lens and a tripod to keep your camera steady and avoid camera shake, you'll need some flowers, plus some glycerine (available from a pharmacy, the baking aisle in a supermarket or online) to create long-lasting, highly reflective droplets. You'll also need a bright source of light – either from a window or an off-camera Canon Speedlite flash.