Ribbons, Laces and Frills

Ribbons and frills have been associated with romance since the days of knighthood when a knight rode into battle with a ribbon or scarf given him by his lady fair. The dictionary states that the word "Lace" comes from a Latin word meaning to "snare" or "noose".

Cupid 

Cupid (Gk. name is Eros) was the son of Venus (Gk. name is Aphrodite) the Roman and Greek goddess of love. In the Roman and Greek myths Cupid is always a youth, never a fat baby with wings. He possessed a bow with a quiver of arrows. When he shot the arrow into someone's heart, that person fell in love. Usually his mother would be the one who sent him on such errands. In Latin, the word Cupid means "desire." Cupid is typically represented as a chubby, naked, winged boy or youth with a mischievous smile. Cherubs are descendants of Cupid. They are depicted as lovable little winged creatures without arrows and quivers. Cherubs were typically not mischievous like Cupid. 

The Rose 

Roses have endured as the traditional flower of Valentine's Day, and perhaps we also owe that to the Romans. In legend, a woman, Rodanthe, was pursued by many suitors who finally became so impassioned they broke down the doors of her house. This enraged the goddess Diana, who turned the woman into a flower and her suitors each into a thorn.
The rose, which is undoubtedly the most popular flower in the world, speaks of love and has been the choice of lovers in every century. If you rearrange the letters of the word rose you get Eros, the god of Love. The color of roses are also important. 

White roses are for true love and purity of the mind.
Red roses are for love and passion.
Yellow roses are for friendship.
Black roses mean farewell.
Pink roses mean friendship or sweetheart.
The message would grow in complexity with combinations. A full rose placed over two buds meant secrecy. Remove the thorns from a rosebud and you say "I fear no longer." Remove the leaves also and your message becomes "There is nothing to hope or fear."  
 
Turtle Doves and Love Birds

It was a popular belief in the olden times that the birds chose their mates on 14th of February. Doves and pigeons mate for life and therefore were used as a symbol of "fidelity."

"Oft have I heard both youth and virgin say
Birds choose their mates, and couples too, this day;
But by their flight I never can divine,
When I shall couple with my Valentine."
Herrick 

Love Knot 

Young women in strict Muslim households used to send their pledges of love to young men through messages woven through the knots of a carpet in an Arab tradition. This tradition of sending messages through the knots gave birth to the concept of love knots that continues to this day.