As the beets boil they absorb the salt and soften, which will make their skins peel off easily. From there, just rinse them under cool water, rub them, and slice them.
Celebrity chef Geoffrey Zakarian revealed in an Instagram post that he uses red wine vinegar, salt, coriander, peppercorns, and sugar in the boiled beet water.
You can add any combination of seasonings that you wish. Add sage, salt, minced garlic, citrus zest, thyme, rosemary, mint, marjoram, or even a little lavender.