best way to stain exterior wood door

It is important to stain your wood exterior doors regularly, not only to protect them from the damage weather can cause, but also to keep your doors looking the best they can by making the wood darker and richer. being visible to the outside world, staining your wood exterior doors should be carried out annually so that the doors remain striking and rich.. We decided on wood vs steel fire doors because of the difficulty of sizing eac door properly. all exterior doors are protected by a roof overhang and wwould rarely get wet except for a windy storm. what will be the best way to protect doors to last? i was thinking 3 coats oil poly. thankj you. Choose a stain that is made specifically for indoor wood (unless this in an exterior wood door) and choose a color that suits your d