When constructing a Pilates program remember it is important to make sure that your workouts are well rounded. The Pilates Method has over 500 exercise when you're using the system as a whole. Make sure to take matwork classes, equipment classes and private sessions in order to achieve the maximum results possible. Each piece of apparatus works the body in a different way so keeping things fresh is important in order to keep the muscles challenged.
Make sure you are not a client that gets stuck in a groove. Some clients only take equipment classes because it's fun to workout on the machines. Some won't take mat classes because they claim they are too challenging. The ideal client should be taking both (or privates) in order to keep obtaining their goals at least 2-3 times a week. Fortunately at the studio clients are able to work on all the apparatus' if they are taking group equipment classes. Certain studios sometimes only offer reformer classes which can limit and constrict your workouts.
Remember Pilates workouts should always be fresh and fun! Mix it up to keep seeing results.