This exercise is great because you can leverage the weight of your body to help improve hip flexion. This exercise often showcases the discrepancy from side to side.
Start position: Place one foot on an elevated surface, the higher the surface the more aggressive this stretch will become.
The movement: Lower your body as if you are reaching the elbow towards the heel of the elevated leg. Really sink down as far as you can. With each exhale sink a bit deeper. Rotate your hip around to find your restriction!
Programming: Hold for 2 sets of 30-60 seconds