I love this one it looks so easy but there is a lot going on.
You can have your feet hip width apart or together but rembember the knees have to follow the feet so if they are apart make sure the knees do not fold inwards or outwards.
Touch the floor with your finger tips and take your bottom down as though sitting on the edge of a chair (no cheating get that bottom down)
Your bottom should not move from here but bring your hands onto the knees and straighten the arms (you should feel this in the back you need alot of strenght)
Now take the arms up and beside the ears as you look forward.
Keep your breath steady and control the pose.