The glute bridge is one of the most effective exercises to activate the glutes. It's also one of the simplest. Glute activation will always increase your performance potential in the squat, deadlift, and all lower body training, including sprints and jumps. It'll also increase your ability to stabilize your pelvis and lower spine during lower body exercises, which can prevent low back pain and injury.
The one-legged version will activate the anti-rotation capacity of your core muscles. This will also increase hip stability in functional movements.
From a supine (lying on your back) position with your arms overhead and knees bent, simply contract your glutes, then press your hips up.
Hold the contraction in top position for 1-2 seconds before you get back down.
A common mistake is to place the feet too far in front of your hips. This will activate the hamstrings to a higher degree. If your hams are taking over, make sure you place the heels closer to you. Use the arms-over-head position to get a slight mobilization effect for the thoracic spine and chest muscles. Everything counts!