Side lying on the floor, locate the hip bone. Place the ball just above that so that it is lying above the hip bone at the top of the thigh and the pelvis.
Put pressure on the ball by rolling over onto the side so that the ball is wedged between the floor and the TFL muscle.
This is very often a tender spot so please ease into it gently and don't forget to breathe!
Remember that you are in charge of the pressure. If it's too much then use your arms to take the weight off a little. You are looking for a little discomfort so if there are a few spots that feel uncomfortable (NOT painful) then stay there and breath.
You should feel the discomfort reduce. If it increases then move off and look again. Stay on one side for around 60 seconds as you find a couple of different 'spots' to work on.
You can then move the ball backwards towards your glutes just below the rim of the pelvis. Here you will find the Glute Medius and Glute Minimus. Again these are tender spots so take your time and be gentle.
Repeat as with TFL. Massaging these areas using the tennis balls little and often is best.