This is great for developing rotational power. Back in the day when we had NO equipment, we would hit an old tree in my backyard that was gonna come down.
Now we hit against tractor tires which is more forgiving on the wrists.
Allow your feet to naturally pivot as you swing and rotate.
Your top hand can either stay towards the hammer / top end or you can allow the top hand to slide downward as you swing.
Begin with your weaker side and perform equal reps on both sides.
High reps are preferred for improving conditioning, grip endurance and rotational power.