Decide which type of yoga you need. Each type of yoga has its own particular benefits. As a versatile activity you can focus on Muscle and Body Image, Cardio and Weight loss, Flexibility and Relaxation. Think about what aspect you need now and put your effort into the right style.
Muscle and Body Image: If you are seeking to gain muscle you might want to engage in yogalates which is blend of yoga and Pilates. Another option is power yoga which helps you hold your position for a time engaging your core muscles.
Cardio and Weight Loss: Yoga that focuses on cardio is faster paced and helps you build up a sweat. You won't hold positions for too long unless they push your body. Movements are quick and designed to get your heart pumping.
Flexibility: Most yoga is designed for flexibility but certain practices emphasize this more than others. They can focus on hamstrings, lower back, upper body, etc. Slower elongating movements are common.
Relaxation: At its earliest forms Yoga was a meditative practice mixed with certain religious practices. Even though the religious component has been removed in Western nations the meditative types have caught on.