Depends on the firearm for me.
My shotgun, safety is always on when it's not in use.
My Glock and Sig obviously don't have safeties.
My Walther PPK, it depends on the situation. If it's on the nightstand, the safety is on. If I'm carrying, occasionally I keep the safety off (it has a long DA first trigger pull, so I'm not that concerned with a ND drawing/holstering)