One of the main principles of the Feldenkrais Method(R) is to use the entire skeleton to support an action. Although it may seem strange, this includes a stretch. Awareness Through Movement or Functional integration (R) lessons subtly communicate with the nervous system to make connections with other parts to gain support. For example, showing the nervous system how the legs can use the pelvis for support could allow the hamstrings to lengthen and allow for higher battements (kicks).
Another principle is to help the nervous system differentiate between the various parts. Often, when one muscle moves, others contract as well, to support the action. Dr. Feldenkrais called this "parasitic contractions." In this case, moving the other parts around the stretched muscle can help it to release more. For example, if you were in a forward lunge to stretch your psoas muscle, you could make tiny circles with your back heel or very subtly tuck and release the pelvis while in the stretch and you will find you will easily deepen the stretch.
Static stretches are the least effective way to lengthen your muscles. The traditional manner of going to your limit and holding there only helps to set that point as your maximum stretch for your nervous system. Instead, add tiny movements to any and all of your stretches. If you are stretching your calf muscle, play with lightly moving your ankle around while in the stretch or wiggling your toes. If you are stretching your shoulders, turn your head from side to side, rotate your wrists or bend from side to side.
If there is a particular stretch you'd like to improve, ask your Feldenkrais practitioner if he or she can teach you and ATM that would help you to improve that area.
There is a published study on how Awareness Through Movement lessons can lengthen the hamstrings.