Drawing requires feelings more than imagination. Try to express your feelings. For example, if your drawing a tree, you can have a bright tall and blooming tree or you can have a skinny, bent tree. Its not about what you draw, its about how you draw it. So basically your can draw the same thing 100 times and be able to have drawn 100 totally different pictures.
Play games that make you think outside of the box and be creative. Pictionary, Charades, Cranium.... or you could make up your own to play with friends and family! Browse sites like deviant art and look at other people's art/drawings for inspiration.
look at something around the house or outside that inspires you
Don't limit yourself, let your imagination go wild
love deviant art!