I prefer two mirrors as well because I think it gives a more balanced look and it provides defined spaces, his and hers in our case. Your statement about wanting to make it so that 3 people can use it is what has me curious though, is this a what if type scenario or is a 3rd person actually going to be in there all the time? The reason I ask is because DH and I used to make choices based on the what if's a lot. We'd spend the money or compromise on what we really wanted only to never have those "what if's" materialize. We bought a crew cab truck so if we needed to we could tote people but never once did anyone sit back there. We turned a room (that could have been my craft room) in to a guest room and in 10 years it's only been used a handful of times and an air mattress would have worked just as well. So if you want the big mirror because it will actually be used in the context you're planning for, great...then there's a need and that would be the more functional choice for your situation, but if you're just thinking well maybe 3 people might need it, then don't focus on that and do what is more practical for your every day living. KWIM? (And Ida is right, about the two lights)

I don't know that I would try to hang two mirrors in such a small space. I think it may just accentuate the fact that your vanity is too small to have two sinks in it. I would get one large mirror centered with the entire vanity. I wouldn't pay for something custom, there are a million large mirrors out there.

We will have a double vanity with two 36” cabinets with a 24” bank of drawers in the middle. Are these one connected piece or three separate items? If they're separate, that's a lot to take in visually, and -- if so -- you should keep the mirror and lights very simple /calm to balance out. We currently have one giant mirror Why not stick with the one giant mirror? With its larger view, you can see not only your face but also your outfit. It allows you a view of yourself without standing directly in front of it, and it makes the room look larger /brighter. In contrast, separate mirrors -- though trendy at the moment -- will add even more "pieces" to an already complex area. You can bring one large mirror all the way down to the cabinet, eliminating the "break" between counter top and mirror. The contractor wanted to put up mirrors with clips but I was hoping to find something a little prettier! Well, he's trying to do the easiest thing so he can finish with you and move on to the next paying customer. What matters more is that the mirror is "framed" -- either with an actual frame or more subtly with a bevel. This isn't a small detail, and it elevates your mirror from builder-basic. Someone else brought up lighting: I'd go with pendant lights at "eye level" -- this'll give you light at the spot you need it and will eliminate the shadows that come from overhead lighting. But if you stick with the big mirror, definitely put them on a dimmer, as they will be "doubled" in the mirror. No problem with having a separate light above the mirror -- just put them on separate controls. As we age, more light is more better. Bringing up one more detail: Consider mounting your faucets on the wall. This will make cleaning easier, as you won't have to clean around them as you wipe the counter top. If you can't do that, at least go with wide-spread faucets, which don't have to be "flossed" while you clean.

One thing to keep in mind if you're going with Theresa Peterson's recommendation is location of any power outlets, if you have any - need to make sure that they remain accessible. You can always hang the mirror(s) above them, but then the mirror(s) may be too high. I have that issue with my currently remodeled master (this is the "before" photo) - because of the power outlets, and because each mirror needs to be centered with its respective faucet, I cannot do wider mirrors (even though I have the space, theoretically):