The Alexander Technique uses your movements (and postures) as a framework to enhance awareness of the connection between thought and physical action.
With skill, it also uses conscious intention to influence changes in your coordination; one typically in line with the end goal to enhance your movements in any activity.
Most typically, everyday movements (or utilitarian movement) provides the main source of content to apply the technique to. This is great because for the majority of your day we're usually just running the same old patterns of movement and posture, so to positively influence that even slightly can really add up.
That said, the times when I've made the biggest leaps in my development have been when I also applied it to the larger concept of movement in general. For instance, applying the Alexander Technique to running, or swimming, or dancing, or working out all give you plenty of 'content' to explore and develop your own skill and coordination with many side benefits. Often, I find students shy away from applying the Alexander Technique to these activities for fear of 'doing it wrong'; but they miss out on the oppourtunity to discover how to 'do it right'.
The Alexander Technique was created with movement in mind, and is designed so that all your movements and activities become a playground for self-understanding, exploration, and development.
So what do you want to apply it to? What movements are you going to grow through?