Savannah Baron keeps an exhaustive spreadsheet of perfect gifts: a camping chair love seat for the couple who enjoys the outdoors; a refillable candle for your eco-conscious cousin; a cocktail infusion kit for the friend who’s into mixology. It’s not for her. It’s for her 189,000 TikTok followers. Baron, 27, derives a certain satisfaction in “finding those little things and little brands” that could easily be overlooked. But her TikTok videos of curated gift ideas tap into a crucial and increasingly younger audience: People who do their holiday shopping — from inspiration to purchase — on social media. Research shows 60 percent of Gen Z (born from 1997 to 2012) and 56 percent of millennials (1981 to 1996) will do at least some holiday shopping on TikTok, Instagram, YouTube and similar apps, according to the consulting firm Deloitte.