Perhaps one of the easiest binding yoga poses is Modified Marichyasana B.
This is simply Marichyasana B done with the non-marichyasana leg not in the Lotus position.
One reason for doing this pose is that you can't do lotus, perhaps your knees are hurt by it, but you still want to bind. As mentioned, it is one of the easier poses to bind in, and so another reason to use it is so that you can get a feel for how binding affects you body, allowing some muscles to relax (which would otherwise be active without the bind) and forcing other muscles to work (for instance, the muscles that you use to grip with.)
Because this bind is relatively simple and relatively easy I often use it as part of a "warm up."
In the modified version the non marichyasana leg is in a janu sirsasana position, tucked behind the foot of the marichyasana leg.
With the legs in position, the first action is to lean forwards, allowing your hips to lift.
As you lean forwards, you can use your arm on the open side to help support your upper body. Another option is to press down with your bottom knee so that you use your bottom leg to help support you.
These two pictures show the pose from opposite sides.
Note that in the first picture the arm that you can't see is being used to support the body with the elbow straight.
In the second picture it's obvious that I'm resting some of my weight on my elbow.
You can now reach your inside arm (the arm on the marichyasana-leg-side) forwards, to the inside of the marichyasana leg.
Hold for a few breaths and get used to the feeling of length in your arm and upper body.
Next, reach the arm to the side, in front of your shin, while keeping the feeling of length in your spine and arm.
You may find it helpful to pull the knee inwards, towards your torso using your other hand.
You can hold this position for a few breaths, then:
Now you can try and grab the wrist of your other hand behind your back.
Once you have the bind you can turn your ribcage away from the marichyasana leg so that it faces the side. This may make it easier to maintain the bind.
To stretch the shoulder pull your ribcage back away from your marichyasana shin.
After a few breaths here, you can try turning your ribcage so that it faces forwards. You could also try bending forwards.
You can keep your pelvis lifted in this modification or you like let it sink down to the floor.
If you do want to sink your pelvis down, use the bottom leg to help lower your pelvis with control.
If you choose to bend forwards in this modified marichyasana B position, one option is to press your upper arm backwards against the shin of your marichyasana leg. You probably find that you have to stabilize your leg against this push, but you can then use that action to help deepen your forward bend.
Do exercise your awareness. Apply pressure smoothly and gradually so that you can stop if you feel sharp pain or excessive tension in your joints (hip, knee, shoulder, elbow)
Why improve muscle control?
Muscle control not only helps you to control your body, it also helps you to feel it.
Muscle activation creates the tension that not only moves your body, but helps you to "sense" it.
With better muscle control you can use your body with less effort and make it easier to balance, improve flexibility and deal with pain and poor posture.