The lover's stone is lapis lazuli. You can get necklaces in lapis and other jewelry, but you would write on the card what lapis is. The monkey is the symbol that he is universally beloved, that he is a real doll. Vanilla is comforting. Peppermint is invigorating.
Lavender is for happiness and is also a sedative.
A rose is for truth, beauty, and love. I am just referring to a few sentiments available. My book, The Language of Gifts , contains many more symbols. Essence is good, or give a ring. Any gem is a symbol of essence.