forget the sconces unless you do a double in between the mirrors. (are the mirrors/medicine cab lit at all? if not, you might want to consider that option)
Having the back lit, or front lit mirror is great for doing your face or hair.
otherwise, I'd do double lights over each mirror
almost identical to your layout. this vanity layout is beautiful.
or, try what they've done here and get a 4-light fixture centered between the two.
if you want more countertop space, have your faucets wall mounted. I did mine this way and love how easy it is to clean.
few more examples of wall mount faucet and double or single lights over the mirrors.
if you don't want to do the wall mount, then do a wide spread, simple type of faucet.
you can choose to do a tile backsplash if you like
wall mount faucet, tile backsplash and pendant lighting. you could also do this on either end. what I would suggest is recessed lighting in the ceiling to give you extra light.
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navy blue vanity
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