There are several styles of capos out there. We like the trigger-style capos from Dunlop because they can be clamped on quickly and easily, without bending the strings.
For best results, you will need to choose a capo that matches the shape of your guitar’s neck. Look along the length of your guitar’s neck and see how it is shaped along the width of the fretboard. If the top surface of the neck is perfectly flat, you will want the flat capo. If there is a bit of arch to the top of the neck, you will need the curved capo. Also, different capos are used for electric and classical guitars to accommodate the unique sizes of these instruments.
A good capo is a must for many guitarists. Give one of these a try.