Stevens advises warming up even before you stretch - this will prepare your muscles for stretching and reduce the risk of injury.
Make sure to hold each stretch for at least 30 seconds to allow your muscles to relax and lengthen, and similarly, make sure to stretch gently - "avoid bouncing or forcing the stretch," the PT recommends.
Next, make sure to remember that stretching should not be painful - "if it hurts, ease up or stop."
Lastly, do consult a professional if you have any queries. "Remember, stretching is not always appropriate for everyone and in some cases, it can be contraindicated. Always check with a medical professional before starting a stretching routine."