Pick an oversized pattern for your flooring rather than one that is tiny or busy. This makes rooms appear larger than they actually are, as suggested by the World Floor Covering Association.
Install ceramic or other types of tile in a diagonal direction on the floor. This makes it look intriguing and draws the eye visually across the length of the room.
Pick a pale or light neutral shade for the flooring if the walls are an intense color to visually open the room. This method works in the same way if you select dark flooring for a room in which walls are covered in a pale paint or wallpaper. This provides contrast and interest in the space.
Lay hardwood flooring in a manner that enhances rather than detracts from the room size. Install the planks so that they go in the same direction as the longest section of the room, as suggested by The Money Pit.