The "other" end of the bo is the key. As Reiki says, it depends on the strike. In the 4 bo katas I know the rear hand, which does the real work*, almost always winds up:
1) on the hip of the same side
2) under the opposite armpit
3) in front on my sternum, with the palm out
* the best bo kata I know is Urichi ("Back of the") Bo.