Ah, the holidays. Shopping, entertaining, traveling and, you guessed it, gift-giving. When it comes time to think about sharing a little something extra with sitters, nannies and other caregivers, that’s when some confusion sets in. “How much should I tip my sitter or nanny at the end of the year” is a common question, but the answer isn’t cut and dried. There’s definitely no specific number, percentage or one-size-fits-all sum, but there are a few…