My least favorite facing is on women's shirts. Men's shirts don't have facings, why do pattern companies continue to draft women's blouses with facings? I always ignore the directions and double fold the front band, or sew a band on. Examining a similar RTW garment helps in deciding how to eschew facings.
Facings do have their uses: in jackets, waistbands, when making scalloped hems or trim, absolutely. Hem facings can be very useful on hems, to prevent wear or when your'e short of fabric. Some pre-50s vintage patterns are best sewn as the directions dictate, facings and all, and that I don't mind.
*Vintage Knitting: I'm translating a German pattern for knitted lace chemise or blouse trim. The garment is then sewn onto the trim. The patterns are under copyright but I'd be happy to share a synopsis of the construction techniques, if anyone is interested. I should check Google archives, since I know Godey's Lady's Book and similar publications have such patterns.
I've been sewing and hope to have a finished garment to share by tomorrow :)