For me Myofascial release has been the exercise/stretches that have given me the best results. And the best applications of Myofascial release have been from both a skilled Active Release Technique ART practitioner and a massage therapist, skilled in deep tissue massage. I also use a foam roller to do it myself, but it is not as effective, as I cannot achieve the same positions and pressure, but I can do it more often and when I want. I also had a cortisone injection in my hip socket last week, besides relieving the pain it also gave me noticeably more range of motion, which was a pleasant surprise.
Here are some links regarding myofascial release .
http://breakingmuscle.com/mobility-reco ... o-athleteshttp://breakingmuscle.com/mobility-reco ... es-it-hurt