Any 18 or 21 year old is extremely hard to buy for, why not forget the money in the card and give them a one-of-a-kind 3 tier tower full of goodies.
Each tower is custom made to order so you may request items you would prefer and can add more or no alcohol, but typically the tower will include;
makeup (lip gloss, mascara, tinted blush) will not be outrageous items, will suit age range.
nail polish and nail accessories
bath and shower goodies (bath bombs, face masks etc)
chocolate and sweets
cocktails in a can (alcopops) can request without
mini-celebration bubbles (non-alcoholic on request)
topped with 18, 21 or name banner and curly ribbon.