You should work on the posing of the human figure. There are a number of tutorials available on the internet. In this particular case, the arm on our left is much longer than the one on our right. Also, they both look like right arms. Try posing yourself in what you intend to draw to get an idea of how the arms naturally angle themselves. You may also want to draw your own hand a few times so you are familiar with that particularly tricky part of the body. Hope this helps.