How should I use tape therapy for knees or other joints?

Not too long.. The purpose of tape therapy from an initial injury is to provide stabilization of a sprain. Although research has not proven complete efficacy in recovery time, it can help. The downside of using such as a ace wrap is the restriction of blood flow if worn too tight or prolonged.
Kinesiotape. Kinesiotape or rock tape should be used in conjunction with pt or a guided strengthening and rehab program. The tape gives you biofeedback and helps your body adjust alignment. But it does get loose and should never be used by someone inexperienced in its application.