1) It takes Practice to develop and maintain a Practice
The time you spend on the yoga mat is a practice to help you witness your life, from moment to moment. Developing and maintaining a consistent and healthy practice is an ongoing process, and in reality is a complex relationship with yourself. And, just like any discipline, it takes practice (consistent repetition) to have a practice.
We often hear students and colleagues talk about how difficult it can be to just get on the yoga mat, much less do the actual asana practice. However, almost everyone agrees that once you can get yourself on the mat and do your practice for that day, whatever that might be, you never regret it. So, the one of the biggest challenges in any practice is to simply begin. In effect, much of the "practice" to maintain a practice is focused on developing habits to reinforce your yoga practice in your daily life.
These habits can be as simple as: developing a routine for making sure you get out of bed when the early morning alarm clock goes off; to scheduling your eating and meals around your "mat time"; to reviewing your work week one week in advance and scheduling the class or classes which you're going to attend. Different techniques work for different people, and everyone has to develop their own. In any case, the best advice we've received from a teacher is to "always leave your mat a little bit hungry, so that you'll want to return the next day." Start slow, be content with steady progress, and most of all have fun!

2) A Metaphor for Practice
Imagine that someone approached you and offered you a brand new car; and further told you that this car was magical. It's called a Self-Realization car, and comes with the following money-back guarantee: "If driven faithfully and consistently, this car is guaranteed to lead you to complete realization of your True Self".
"Wow!" you say, "That's some car! What's the catch?" Well, as we know, there's always a catch, and the person says, "We can't predict how long you'll have to drive the car, or in what direction, in order to achieve complete realization of your True Self. We just guarantee that it will happen eventually if you drive this car with faith and consistency. And, by the way, it's up to you to keep it in good working order. We don't perform repairs on our cars, and you're not allowed to trade it in on a new model if this one breaks down." Well, that's a pretty big "catch", but you still decide to take the car because the potential payback (Self-Realization) is too much to pass up. We don't know about you, but with that type of money-back guarantee, we would make sure that the car was always fueled up and meticulously maintained in superb working order. We'd also be sure to drive it on a daily basis.
Obviously, the Self-Realization car is a metaphor for your daily Yoga practice, and we certainly believe that Ashtanga Vinyasa Yoga is a "vehicle" that can take you to direct experience of your True Self. However, just like the car, it's impossible to predict how long it will take, or the directions and destinations required during the journey. In addition, you are the only person that can (or will) keep your practice in good working order. Integrating the following elements into your daily path of self-inquiry will promote a healthy, vibrant practice: faith, devotion, consistency, a sense of humor, and fun!
That said, we also know that even the best maintained cars sometimes breakdown or need minor repairs or overhauls. It's the same with your yoga practice. It's important to refresh your practice routine when it gets boring or stagnant. Rekindle the flame of your individual practice by modifying your routine, forming a regular practice group with friends, or taking a workshop, retreat, or yoga vacation. Find out what works for you, but most of all enjoy the journey!

3) Thoughts on Practice
Establish a clear Intention for every practice: The desire for personal growth and progress is common to us all; and maintaining steady growth and progress in our practice is one of the most positive reinforcements. It's easy to get discouraged if we perceive that we're not making progress. However, as the saying goes, "Practice doesn't make perfect, perfect practice makes perfect." Setting a clear intention for your daily practice is a powerful technique to promote mindfulness. Simply choose one or two elements to serve as the focal point for the day's practice and then continually come back to them as your mind and breath drift. A clear intention is your best bet to a productive practice. Examples could include the following:
• Maintaining equal breathing through both nostrils.
• Focus on keeping the inhale and exhale equal length and depth.
• Concentrating on vinyasa, and having the breath initiate and complete every movement.
• Working on core strength during flow-throughs.
• Visualizing a movement and/or asana just prior to initiating it.
• Focusing on one or two foundational alignment principles during problematic asanas.

Try to observe your practice without judging it: In many ways, we are what we think; thus, paying close attention to both how we think about our practice, and what we think during our practice is extremely important. Making negative self-judgements before, during, or after practice is counterproductive, and will slowly become a cancer eroding your self-confidence and self-esteem; and preventing progress. Eventually you might become so discouraged that you'll give up. Be positive and accepting in your approach. Yoga is a path of self-inquiry, not self-bashing. Observe the process and respond with self-love. Remember, your practice changes from day-to-day; and in fact from moment-to-moment. When we observe a process objectively, we can learn, change, and grow, but negative judgements simply defeat us.