Sometimes we lean too hard where we think the support is and throw ourselves off balance entirely. This kind of interaction wastes energy, and ruins relationships. No one else can give you the map, but teachers (and fellow beings) can help you with your map reading skills. I believe the map actually begins to draw itself as we as make our own inquiries. It is convenient to begin with the body, since we each live in one through which we accumulate experiences. I have taken plenty of yoga classes that felt like they were all about the body.
When I started going to yoga classes, I had trouble communicating with my toes. I'd ask them to leave the floor and spread wide and they just looked back at me until I laughed. The same thing happened when I wanted to move my rib cage in small circles, or lift my legs in anything resembling Navasana (boat pose). I could make a long list of what wasn't happening and what was happening. The mind woke up to the shock that I was living in a body I really didn't know, even after all this time and all we'd been through together. There were flexibilities I never realized, and abilities to match the inabilities. There are ways of hearing that internal voice that wants to share who I really am, and allowing stillness, along with unifying movements helps develop the level of consciousness where the inner voice can speak.
In my own practice a shift began as I realized that it is not strength or will that lifts the body, but the ability to allow energy to rise from a foundation of support. It may seem hokey, but even holding oneself on hands and knees and lifting one hand will help inform the body about where the support is really coming from -- the core and the breath. As awareness turns the light on, the body can release and relax all the other clenching muscles and allow the core to use the breath. This lift makes the weight resting on the knees and hands actually lighter. Yes, lighter. So it is not always a matter of pressing down into the earth with one or another body part. I suggest softening the foot into the floor and drawing core energy up the body as you lift the other leg into Vrksasana (tree) or fly a bit in a elementary standing version of Balikakasana (crane) and you may find that balance is no longer a struggle.
There is a significant athletic aspect to yoga in this day and age, in this place, and among many students, but really in my view that is not even half the practice. I, too, admire strong, lithe bodies that can achieve amazing things, seem easy and fluid, and exude grace. I have not felt that I lived in one of those, but I am coming to find those attributes exist even in my aging, asymmetrical lived-in-half-century body. I attribute this to my explorations of yoga, which have definitely not been approached as any kind of physical training in any athletic sense, but truly is a methodical opening of the communication and energy channels inside me. The practice helps me learn theinner languages and more fully understand the messages.