Hip Exercises are most effective when you stabilize the pelvis first.
There is no easy answer for that question. Some things to consider beyond good nutrition and some form of daily cardiovascular or resistance training is the quality of your exercises, not necessarily the quantity.
Focus on the pelvis for more effective hip exercises. Why do we want to focus on the pelvis?
A neutral or stable pelvis allows the legs to circulate through a full range of motion, thereby increasing flexibility.
A stable pelvis comes from engaging your abdominal muscles and being aware of the muscles of the pelvic floor (deeply layered in the pelvis). This leads to a stronger core, which, in turn leads to more mobility in the legs for more effective hip exercises.
A neutral pelvis also sets the feet and legs in alignment allowing you to do hip exercises more effectively and efficiently. Muscular imbalance in the pelvis will cause dysfunctional movement patterns throughout the body causing undo problems to arise throughout the body.
Below I have listed various positions that we may do hip exercises and how to first stabilize the pelvis.
Lying Leg Circles:
Why: This is a great hip exercise to stretch, strengthen, and articulate the leg at the hip joint while maintaining a stable pelvis.
Position: Lying on your back with one leg extended out along the mat and the other leg extended into the air at 90 degrees. Stabilize the pelvis by allowing the tailbone to anchor into the mat creating a small arch in the lower back, then just draw the mid part of the ribcage down to engage the abdominals.
Action: Keeping the hips level and torso and leg on the mat acting as an anchor circle the leg in the hip socket. Imagine making big circles on the ceiling with your toes. Circle the leg 4-6 times each direction and then switch legs.
Side Kicks: Small Circles
Why: These hip exercises help to stretch the inner and outer thighs while strengthening the hips, buttocks, and hamstrings. Position: Lie on one side with your shoulders and hips stacked and legs long at a slight angle forward, head rests on the bottom hand.
Action: Squeeze your buttocks as you lengthen the top leg as if being pulled out of the hip socket. Keeping the hips stacked and waist long circle the leg just forward of the bottom foot in a small but vigorous manner. Repeat 10 times in front and 10 times in back of the bottom foot. Avoid rolling the hips forward or backward.
Standing Side Kicks:
Why: This hip exercise improves balance while stretching and strengthening the hips and thighs.
Position: Standing tall with feet together abs engaged and ribs lifted up off the pelvis.
Action: Standing tall on your right leg with hips evenly aligned, swing the left leg straight out to the side. Do not lean to make the leg go higher, it will feel like it just stops at one point. Then swing the heel back in front of the other foot and repeat out to the side for 8-10 repetitions. Repeat on the other side.