How do I spice it up?

i've been with my boyfriend for over a year & i feel like our fire has already been put out. we're both very comfortable with each other but i get really shy so it's hard for me to turn to him and try to turn him on because i'm scared he'll tell me "not tonight"... granted, he's never done that, but the fear is always in my head. how do i get over this and what are some ideas to spice it up???