[color:"green"] I've been practicing Ashtanga for about 3 years now. I love this style because it's something that I find simultaneously relaxing and challenging. The best way to make progress is to practice with a teacher that will push you. In Austin I would go to classes every day at the YogaYoga studio. By choosing to attend certain teacher's classes, I would be pushed to achieve new levels in my practice. Other days I would take a more gentile approach.
Really, you have to stick with it. Don't expect to master advanced poses overnight. It may seem like nothing is changing, then one day you will all of a sudden slide effortlessly into an asana you were unable to do before. I remeber the first day I was able to de headstand. It was such an accomplishment. I couln't wipe the smile off my face for hours. But, that came after doing the preperatory pose for about a year.
Now that I've moved, I haven't been to an actual yoga class in Paris. I have a home practice using dvd's. If you haven't tried hatha flow, it is a nice compliment to ashtanga, for days when you want to mix it up and play with new poses. Stick with it. You'll slowly see changes. Namaste! [/color]