My home has security bars over the windows, and a wrought iron security door in front of my front door. Wow, that sounds kinda confusing. At any rate, that security door is only unlockable with a key, so it provides the "First line of defense " if you will. My front door is of the solid no window variety, but does have a peep hole. Lastly, I have an old B/W security camera setup so that it looks out of my living room window (which is directly to the left of my front door) right at anyone who comes to the door, as well as a bit of the surrounding area.
Typically if someone rings at night, I have the shades/curtains closed so no one can see in, so I look at the security monitor which is also in the living room to see whom it is, followed by looking out the peep hole. If I know them, great, if not..... off they go. I usually wont answer if I don't know who it is, especially at night. My two dogs go nuts when the bell rings so that usually makes anyone ringing step back a few paces from the door (even though there are two doors in the way, lol!). If for whatever reason I choose to answer it after checking the camera and I don't know who it is, I'll crack the inner front door enough to show my face and see what they want (and my dogs are usually trying to push their way between my legs, the silly beasts). Its nice having that wrought iron door, since I know unless they have a key or are going to attach cables to pull it down, no one is coming through it unless we let them.
Where does my gun play in all of this? If it's not on me at home, its on whatever coffee table/table/ desk im sitting in front of and gets picked and held out of sight if its someone I don't know. The Mrs. Pretty much follows the same course of action as well.
During the day when I have my window coverings open, I more or less see the person coming if im in the living room, and they usually see me. I'll normally just answer it in the same fashion as stated above.
I honestly have to say that I never considered what a bad guy/ burglar might think if no one answers the door. Oops! I hope my dogs barking helps with that. Duly noted from now on.
