I've been using hoods to conceal my characters' faces when they're incognito, but is that not feasible? Would it interfere with the horns? (The hoods aren't attached to cloaks since that would impede flight.) If not hoods, what then? Use my avatar for reference as to what my dragons look like.
Wait, what if there were slits for the horns? Long ones so the wearer could move the hood up and down? Would it be too loose or revealing of the face? Also, I need a reason for hoods to be a common occurrence and not a cause for immediate suspicion.
Clear eyelids maybe? They wear hoods to block out some sun when it's too bright? And I don't think slits would be too revealing. I do wonder though about if just concealing the face would not be enough. Seems like there might be more variation and more easily identified by stuff other than facial features. The horns for one, scale color, etc.
What if they were dressed in obviously fake dragon costumes, and you take off the costume to find a real dragon.
My dragons are all the same color within species. Scale shade determines age for the most part-- scales grow more vibrant until maturity is reached; after their prime they grow paler. Horns might be damning if they're distinctive enough; for example, horns betray gender (so do tail tips.) Also, if someone's horn is broken, it's also distinctive. Also, build might give them away-- an excessively skinny dragon for example or a muscular type might be recognizable based on their body. Also, if you've got a deformed or injured or otherwise unusual wing, you're screwed. Maybe I need to address body disguise too. Other than robes, how might they go about that without having it be suspicious? The thing about slits that I was concerned about was that the longer the slit, the wider it can open (although a stiff material would minimize this problem) so if, say, it's a windy day and you happen to see a little too much of their eyes and recognize them.
How much do your dragons live by sight? If they perceive the world primarily through scent, then masking one's odor would be more important than masking one's appearance. Basically, imagine a human wearing an obviously fake human mask. Same principle applies.
Odor doesn't play a factor in identification, though I've been toying with the idea of using it for purposes of attraction, like pheromones. As for the mask... I'm looking for something you might wear for purposes other than disguise so people don't get suspicious, but is ideal for that purpose. I don't think you'd wear a mask for anything other than disguise, so that would draw immediate suspicion.
They assume nothing... Really how do you hide a snout? Unless you have some form of enchantment, or surgery, they are gonna know its a dragon. Putting a mask on a dragon will just seem comical, when magic is probably a thing.
I'm not looking to disguise the fact that a dragon IS a dragon. Literally everyone else is a dragon, so they would KNOW that. I'm just looking to have a dragon not look over at a guy across the bar and think, "Hey, what's Bob doing here?"
Dragons fly. They might fly pretty fast. So I'd think that "masks", in the sense of the mask of a suit of armor or, for a more modern analogy, a sports helmet, might make perfect sense, as a protection against debris, rain, hail, etc.
Looking for mundane options. In my world they're going through a dark age of magic and the general population doesn't know it exists. So I would need a non-magical explanation at the very least.
You know what, that did cross my mind now that I think about it and I'll definitely consider them. Is there a reason to wear a mask indoors, though, or just walking down the street (for whatever reason that you're walking instead of flying?) The armor concept would also work well for the body too, except it's too impractical. Who wants to put on a full suit of armor to go out unless they're a soldier or a cop? I want something sort of minimalist for body attire; something one-piece like a robe, but not a robe since those would create a ton of drag on flying excursions. Drag on? Dragon? Too forced?
An alchemical potion? Something they drink? Like for example the Harry Potter potion that allows them to change into another person for a little while.
Masks for fashion/modesty/religious reasons: Everyone wears them, pretty much all the time, except when at home. Kind of like a Muslim burqa, but not limited to the females. In In Conquest Born, by C.S. Friedman, the noble ruling class of Braxana (a racial and social designation) always wear full body coverings of dark grey wool and leather, no matter what the temperature. Furthermore, since one of their racial characteristics (they're human, but maintain a rigid caste system) is pale skin, they also always supplement their natural whiteness with a heavy coat of white makeup. But back to the clothing, there's a scene when Zatar, one of the leaders of the Holding, enters the home of another Braxana who is a bit of a degenerate. The homeowner peels off his gloves, which is legal within his own home, but Zatar scoffs at him and says something along the lines of "Are you trying to shock me? We've all seen men ungloved before." So make masks the default, but apply sumptuary laws to them that govern who is legally allowed to wear what colors, materials, and designs. A rich dragon could then go "incognito" by putting on a simple canvas mask, rather than one appropriate to his station and rank. A poor dragon who tried to do the reverse, of course, would face serious penalties. ETA: Horns could likewise be concealed/augmented by wearing sheaths equivalent to koteka (link is to Wikipedia, but there is an image that includes a view of a man's scrotum) "penis gourds" that the men of certain tribes in Papua New Guinea wear. I mean, would you want your spouse just flying down to the market for some fresh dwarf meat with his/her horns hanging out in the breeze for everyone to see? I didn't think so.
It's a good idea, but I don't think it would work. My dragons aren't too concerned with modesty other than their genitalia, and those are hidden in a pocket under their skin where nobody can see them unless they pull them out, and they don't have a religion of worship (although they do believe in a creator, at least most of them do.) I don't know how I feel about absolutely everyone wearing this method of disguise, either. I just want it to be common enough that if you see someone wearing one you don't assume they're hiding something. But that's very interesting and I like the concept. I think I'll use it for another book.
At this point, I think you need to give up the idea the dragons in your would could conceal their faces. Because its seemingly looks like an impossible feat right now.