The important points to remember are that you make sure you don't lean forward in an effort to reach lower, doing this can cause strains. Your feet should be planted corecctly and not rolling inwards. The first position is to have your hand on your thigh and it is fine to stay there if that is where your comfort is. It's a good idea to try this pose against a wall ensuring that your back is flat against the wall as you bend sideways. You'll know that's the right position then.