A student said she had a pattern of waking up in the early hours of the morning and not being able to sleep again.

Doing some yoga before sleeping can help.  Avoid energising poses like the downward facing dog. Try instead Uttanasana the forward fold or Paschimottanasana, the forward bend from a sitting position.

With these forward bending poses, remember to move the hips into dog-tilt and breath to the first energy centre —muladara chakra, situated at the top of the cervix for women and just behind the perineum for men. Afterwards, do the child posture. You can also sit cross-legged and meditate (focus on the breathing and allowing more breath in on each inhalation and more breath to move out when you exhale).