When selecting outdoor bar stools, it is important to consider features such as material, comfort, height, style, maintenance, and portability. Look for durable and weather-resistant materials such as teak, metal, or synthetic wicker, and choose a style that complements your outdoor decor. Ensure the height of the stool is appropriate for your bar or counter, and consider features such as padded seats, footrests, and ergonomically designed seats. Make sure the stools are easy to clean and maintain, and consider portability if you plan to move them frequently.