Cake is Always a Good Idea
For everyone a birthday signifies a birthday cake, candles, balloons, and a grand party wherein friends and family converge to wish birthday wishes to the birthday person and join in the celebration. More than that, it has become customary over the years to give something to the birthday person as a token of affection and love on their special day.
Acknowledgement in line with the tradition is more or less in the form of a birthday gift that brings smiles and showers love, underlying the depth of feelings of true affection for the birthday person. Even a mere card or a bouquet of flowers is enough to eject a smile on the birthday person and his acknowledgement of your feelings for him/her.