Put some objects in a kind of orderly structure and quickly draw/sketch what you see.
Check this site for some examples of what still-life looks like: www.tate.org.uk/art/artworks/morandi-still-life-n05782
A still life (plural still lifes) is a work of art depicting mostly inanimate subject matter, typically commonplace objects which may be either natural (food, flowers
(wikipedia knows more about this)
Photo credit: Photo Still Life by cogdog on Flickr