how old is ur bf now?
if he's 18 yrs old, just get in 18 different present and put it in a cute present box... the 18 different present can be chocolate, key chain, ur photo wit him, a b'day card, lighter (as u said he smoke), t-shirt, facial form, shaver, etc... 18 small small present all together... he sure will feel touch.. coz i tried this b4..