Most people learn pretty quickly that comfort is crucial when you practice sitting meditation. Maintaining your natural spinal curves in meditation is the key to ease in sitting. The key, even if your hips are very flexible, is making sure your pelvis is higher than your ankles.
You can accomplish your perfect sitting position in many ways—by sitting on a Zafu, a Zen Pillow, Meditation Bench or a V-Shaped Meditation Cushion. Depending on the structure of your hip joints—which is unique to all of us—the V-Shaped Cushion may be a great, supportive choice for your sitting practice.