Iliotibial band syndrome is characterized by lateral knee pain that is generally non traumatic and associated with overuse.
The iliotibial band is a piece of connective tissue that runs down the outside/lateral part of your leg.
It connects your hip and you knee.
The band connects into the side of your knee and can rub and create friction and swelling causing pain.
The ITB is a unique connective tissue structure with some properties of a tendon, others of a ligament, and an unusual tension control system consisting of a couple of hip muscles at the upper end, and it probably does not slide significantly over the side of the knee.
Stretching in general can help. A combination of dynamic and static stretching focused on hip and ankle is probably your best bet.
It is likely to provide some temporary relief and should be part of an active recovery day. Foam rolling your thigh muscles for 30sec to 2 mins might help loosen things off. Follow this link to my YouTube videos on stretching and foam rolling
This depends on the nature and chronicity of the knee pain. Pain can last from weeks to months. This is going to be a case by case answer