Description
If your character requires a handgun, then without doubt they will require a holster.
Even if not used, the correct holster will help make the character more believable. Whether they be a soldier or police officer with one fixed on their webbing/belt rig, or even a detective or spy with a discrete shoulder holster.
All to often the selection of a holster is left to the costume department, which rarely marries up with the size/shape of the weapon the character is actually using.