First tip for new sex doll buyers. The size and body shape of a realistic sex doll are factors that must be considered when buying, as they have a significant impact on your sexual experience. Choose a size that is right for you and matches your personal preferences. Do you prefer a smaller doll or a larger doll? Do you want a doll that is your size, or one that is taller or smaller than you? The right body size is an important factor in having a good use experience.