Sit comfortably on the floor. If the backs of your legs are really tight and you find yourself slumping, sit on a pillow so you can keep your spine straight.
Fold your right leg in and reach your left leg long.
Wrap a yoga strap or Theraband (or an old tie or belt from your bathrobe) around the ball of your left foot.
Use the strap to pull your toes toward your head.
Do not jam your knee into the floor, and keep your left heel on the ground.
Hold for 20 to 30 seconds, then repeat on the other side.