Typically, there are two major types of bindings, namely bungees and boots. They are designed for different riders or different riding styles.

Sizes

Bindings which are too loose can be equally dangerous as those which are too tight. Coming out prematurely, or unexpectedly, can be more dangerous than staying in. People may twist their ankles really bad when only one foot comes out of the binding and the board continues to twist the other foot. Worst still, both feet comes out and the board hits them in the head. On the contrary, tight bindings can cause bruises on your feet. So, it is important to pick bindings that fit your feet the best and is adjustable for comfort.

Usually, bindings are available in different sizes depending on the type of bindings and the manufacturer. Bungee bindings are typically free size for all, adjustable bindings are available in about 3 different sizes and the high back bindings have up to 7 sizes. Below is a binding sizes reference.

Bindings have some adjustability for easy on-and-off. If you're using lots of force and soap, then you should consider something bigger or more adjustable.

Components of bindings

Overlay - It provides a lot of foot support by pulling the toe and heel pieces together, and creating a snug, secure connection for your board. Make sure that they should be thick enough to offer support, but not so thick that they don't stretch. Good overlays work effectively by pushing your heel down with closures being cinched down enough for consistent, all-over, non-binding pressure.

Underlay - It makes contact with the top of your foot and the Achilles tendon area. Usually, it is made from some form of EVA, which vary from very flexible to very stiff. A stiffer underlay offers more support at the expense of comfort and ease of on-and-off. Softer underlays will be comfortable but less supportive.

Hardware - It holds the binding pieces together and support to the side of the foot. It is usually made from metal or nylon. Well-designed hardware will fit the shape of your foot by curving into the arch and out at the toes. The heelpiece should sit like a fitted cup and offer support all the way around the heel. Make sure that your foot won't slide on top of any of the hardware pieces. This will cause bruises on your foot.

Baseplate - It must be strong and stiff. The strength and stiffness of a plate depends on the quality and thickness of aluminum. A flexible baseplate will reduce your feel and control over your board. The baseplate should also offer you plenty of stance options.

Footbed - It offers not only a firm support, but also a comfortable resting place for your feet. The heel should sit a little higher than the ball of the foot to accommodate the ankles and knees. The bed should have a nice heel cup to hold you firmly in place. A raise under the toes and an arch support offers you leverage on your toeside edge and prevent you from sliding out the toe hole when your foot gets wet. For shock absorption, make sure the footbed is not too soft. Some manufacturers use two different densities of foam for a combination of comfort and shock absorption while others use air and gel pockets under the heel for added shock absorption.