I decided to hang a mirror close to the where "Alleluia" gets messy the most: the kitchen. It's also near the back door from which we leave the house, so it's a good "last chance" spot to check yourself out (spinach in the teeth? honey on the forehead? cream cheese cheeks?)
This locker mirror was the perfect solution. I bought it at the beginning of the school year for one of our older kids, but she never used it. It has magnets on the back, so it's easily moved. And as you can see, it gets a lot of use!