Generally, initiative for proposals are taken by guys. Not only proposals, even the dates after that are mostly arranged by them. However, even girls should take the initiative of arranging a memorable date for their beloved. In fact, women proudly boast that they have better insight of beauty and esthetics than men.
This idea will work great if you can arrange it during the night. It will be fun to snuggle and watch his favorite flick and his smile, under the sky! You can also plan this for his birthday.
Barbecue on the beach is always a hit, if not possible, carry foodstuff that can remain warm for a long time. You can also implement this plan at midnight to spend time with him under the stars.
Other than these, you can also think of some creative ideas for boyfriend like, decorating his room, when he is not around or making him a collage of your photographs, that he can always keep close to him. Getting a t-shirt printed with a photograph of both of you and personal message is also a great creative idea for your boyfriend.