Hip stretching exercises are important for flexibility and strength.
The reason these muscles, which connect the thighs to the pelvis and spine, need to be exercised and conditioned with lengthening is that your general posture is balanced and stabilized by them.
The Hip Flexors can shorten and lose elasticity if you sit on a chair for several hours a day, or spend many hours driving.
The Gluteus and Piriformis muscles (your butt muscles) can retain chronic tension if not worked out and stretched.
Tight hip muscles lead to loss of balance, tense low back and low back pain, and sore hips that further decrease your desire to stay moving.
The Essentrics Flexibility Workout For Athletes conditions the whole body. This is important because --everything is connected to everything else.The workout emphasizes the lower body yet includes upper exercises.
If you are a beginner I recommend Classical Stretch workouts. The one pictured below shows Miranda Esmonde White stretching the Hip Flexor muscle.
This deep lunge type of stretch can be done after walking, jogging, or any routine workout. Always be well warmed up before you do stretches! You can do stretches halfway through a walk or run, which for some makes the exercise more comfortable.
Here is a detailed description of an exercise that stretches hip flexors.
Scroll down to the last quarter of the blog post - you'll see it!
More Classical Stretch workouts are reviewed at Muscle Stretching Exercises.
I hope these recommendations help with your hip stretching exercises/flexibility!