If your camera gives you control over the aperture, use it. A small aperture (like f/11 or f/22) gives you a relatively large depth of field. That setting will make more of the background identifiable. A large aperture (like f/4) gives you a shallow depth of field. Which do you need for a good dewdrop photo? It depends. This shot, taken with a small aperture of f/16, keeps the whole droplet in focus.