Though one will find tremendous variation in the way that Pilates exercises are presented today, there is a traditional order to the Pilates mat exercises as developed by Joseph Pilates.
Below are samples of the first 10 exercises of a classical Pilates mat workout, including a fundamental warm-up.
At the end of the first 10 exercises, which is meant to be an introduction to the classic order, there is a completed list - with links to instructions for most of the rest of the exercises in a traditional program.
Modifications for the hundred include working with the legs higher, table-top legs, and leaving the head down.
See an Online Video of the Hundred
See Ten Ways to Improve Your Pilates hundred
Supported roll back and chest lift are good training exercises for Roll Up.
Remember, roll over goes only as far as the shoulders. It does not roll up on to the neck.
Modify one leg circle by having the non-working leg bent with the foot flat on the floor. The knee of the working leg can also be slightly bent.
Modifications for rolling like a ball include holding the thighs behind the knees and opening the legs further out from the body. Do not do rolling exercises if you have back or neck problems.
Read: Tips for Rolling Exercises.
Modify single leg stretch by leaving your head down or working with your legs higher.
Also see double leg stretch prep for beginners
Spine stretch rarely needs much modification, but those with tight hamstrings may want to sit on a small lift or have the knees slightly bent. Spine stretch can also be done with the arms lower, finger tips along the floor.
For some, rolling exercises are very hard and for some, they are not healthful for the back. Open leg balance is an alternative to open leg rocker.
The rest of the traditional Pilates mat sequence is as follows:
Get a printable reference list of the classical Pilates mat exercises
Free instructions for most Pilates mat exercises can be found in the Pilates Exercises folder here at pilates.about.com.