The Year of the Perfect Christmas Tree by Gloria Houston, pictures by Barbara Cooney
Makartt 120 Sheets XMAS Stickers 3D Gold & Silver Metallic Snowflake Christmas Tree Nail Art Decorations Wholesale XXB0527
Button Christmas Tree Craft - great fine motor activity too!
Christmas Tree ala Polka Dots Nail Art Design
"Cute Christmas Tree Manicure by Blue Tape & Nail Tips" -- This photo is all the instruction there is.
Nailside: Tape Christmas tree design #Nails
DIY Christmas tree taped manicure (not sure I would actually do this, but the idea is kind of cute)