Try to change your scenery to get new inspirations. A city street may give you ideas for one song, while a park may give you an idea for a totally new one.
Try to put yourself into someone elses shoes. Role playing actually helps when writing music. You may have one set of emotions, but being able to manipulate those feelings is what makes a truly great songwriter.
Use vivid depictions in your song. Think of a glass. When the glass is being flooded with water, a person gets their thirst quenched. When its filled a quarter way, they'll still be wanting more. By using vivid depictions, it helps your audience understand what you are trying to say