A simple idea you can work on when practicing basic balance poses, is the idea of keeping your body still. More precisely, work on keeping your ribcage and pelvis still.
To keep your ribcage and pelvis still, you have to be able to feel them. If you can feel them, you can then notice when they start to move.
You can then work at preventing the movement.
Two very simple yoga balance poses you can do while standing are balancing on the fronts of your feet with heels lifted and balancing on your heels with forefeet lifted.
To focus on balancing on your forefeet, try lifting your heels only a short distance off of the floor and have your knees slightly bent.
Work at keeping your pelvis and ribcage still.
With the heels only slightly lifted you may find that you don't have to worry too much about your calfs and ankles tiring out.
Hold for 5 seconds or more, then slowly relax and then repeat after a brief rest.
Focus on feeling your forefeet press into the floor.
To balance on your heels try pressing through the back part of your heels.
This is going to be a lot harder to keep stay on your heels. However, even though the idea is to keep your ribcage and pelvis still, that doesn't mean that you can't use your arms to help stay balanced.
For more of a challenge you can try balancing on a forefoot or heel with the other foot lifted.
For either of these two balancing poses you can still work at keeping your ribcage and pelvis still.
But so that balance is easier, allow your lifted leg to move to help you stay balanced.
You can also try doing both of these two balancing actions while bent forwards.
If you can't touch the floor when bending forwards use a chair or a set of yoga blocks and place your hands on that.
With hands on the floor or the seat of a chair, first lift your heels.
You may have to shift your hips back so that you can lift your hands.
To lift your hands bend your elbows so that you can keep your ribcage and pelvis still as you lift your hands.
Try to maintain the stillness as you place your hands back on the floor again.
Work at keeping your ribcage and pelvis still even after you place your hands back down again.
Rest for a moment then repeat.
Hold the balancing position for 5 seconds or more.
To balance on your heels first lift your forefeet with hands on the floor or on the edge of a chair.
Then shift your hips back. Notice when your hands relax and stop the backwards movement of your hips at that point.
Try to relax your hands completely while they are still touching the floor, then try a slight lift of your hands by bending your elbows so that your ribcage remains still.
To stay balanced without moving your ribcage try moving your hands back or forwards to compensate.
With your hands only slightly lifted, you can also use your hands to cheat, lightly touching your hands to the floor to prevent falling.
Once you've tried balancing on your forefoot and heel it can be easier to balance with your whole foot on the floor.
To balance on one foot first stand with your knees slightly bent. Shift your weight to one foot keeping your knees bent.
When shifting your weight to one foot, try to keep your upper body vertical.
One suggestion for this exercise and another other "balancing on one foot" pose is to use your forefoot. Even with your heel on the floor try to use your forefoot to help stay balanced.
Try to lift your unweighted foot without allowing your ribcage or pelvis to move. If you can't then you need to shift your upper body further to the side.
Once you can lift your foot, hold for 5 seconds or more and focus on keeping your ribcage and pelvis still.
After 5 seconds or more, touch your foot to the floor without allowing your body to shift.
This is one reason for keeping the standing knee bent, to allow you to easily touch the other foot back down.
To lift the unweighted foot without causing the pelvis to move, focus on bending and lifting the knee (so that the foot follows.)
Note that here again you only have to lift the foot a slight amount, high enough so that it clears the floor is sufficient.
If you find your standing foot gets tired easily, then alternate sides each time.
Note, when lifting your foot, how the foot and ankle of your standing leg activate a little more strongly.
In this standing forward bend, stand with both feet flat on the floor.
Lift your hands by bending your elbows. (Use a chair or yoga blocks if you can't touch your hands to the floor). Then touch your hands to the floor without allowing your pelvis or ribcage to move.
If you press your hands into the floor as if using your arms to help support your upper body, you may find that you can relax your feet.
The trick is to engage them prior to lifting your hands so that your ribcage and pelvis stay still.
The next balancing exercise is to do a forward bend with one foot slightly lifted.
Here again, if you can't touch the floor with your hands with your knees straight, use a chair or yoga blocks.
Starting with your hands on the floor or on the edge of a chair, shift your hips to one side and lift the unweighted leg.
Try to keep the lifted foot pulled forwards as opposed to reaching it back.
Shift your hips back so that you can lift your hands.
Then keep your chest and pelvis still, put your hands back down.
Repeat a few times, lifting and lowering your hands without allowing your hips, ribcage or lifted leg to move. Then repeat on the other side.
Here again, to lift your hands easily, bend your elbows.
A more traditional yoga balance pose is half moon pose.
For this pose and the previous pose, try pressing your forefoot into the floor without lifting your heel.
With your hand on the floor you can relax your forefoot. When lifting your hand, press your forefoot down so that you can lift your hand without allowing your ribcage or your pelvis to move. (That includes not allowing your ribcage to lift!)
Lift and lower your hand a few times, holding it lifted for 5 seconds or more.
Using a chair for Half Moon Pose.
Although not strictly a balance pose, you can try the same idea in cat pose.
Bend the elbow to lift your hand. Then put the hand down again.
Here the idea is to lift one hand while keeping your ribcage and pelvis still.
Repeat the action, holding the hand lifted for 5 seconds or more, and while holding, notice the tension in the arm that is on the floor.
Also notice the difference in tension between the hip on the lifted arm side and the hp (and leg) on the supporting arm side.
You could also do the same exercise but lifting a knee instead.
In this case, so that you can keep your pelvis and ribcage still lift the knee either forwards or rearwards.
The exercises in the videos and ebooks below all focus on helping you to improve some aspect of muscle control so that you can better feel your body and better control it.
The exercises are a little like breathing exercises in that you focus on feeling your muscles activate and relax.
But instead of just feeling and controlling your breath, you work towards feeling and controlling your body.