It may feel good to practice the stretches that are comfortable for you, but it’s important to stretch the muscles that need to be stretched, not just the ones that are already flexible. Stretch both sides of a joint, in order to not develop an imbalance that could lead to injury. Practice stretches that only target the muscles you are trying to lengthen. Isolating a muscle group gives you greater control and means you are able to vary the intensity of the stretch.