Fill the frame with something you find interesting. You could frame simple items from nature, such as pressed leaves, flowers or seashells in a thicker frame. Use a small bit of adhesive to hold the item on a mat or thick piece of paper, then frame the paper. Find a collection of something that seems random, but has a common theme, and frame that, such as old keys or buttons.
Decorate the frame itself and leave it empty. Glue silk flowers, seashells, beads, rhinestones or other small items to the frame. Alternatively, wrap decorative ribbon or a small string of LED lights around the frame.
Display a collection of empty frames for a simple but dramatic look. Choose frames in different sizes and shapes that share a common color or finish. For example, round, oval, square, rectangle, antique, modern, elaborate and simple frames could all work together if they are all silver.
Hang something decorative within an architectural frame. For example, if a section of your walls has a decorative molding frame, hang wall sconces or wrought iron wall sculptures inside. Alternatively, paint the wall with chalkboard paint and use it as a framed chalkboard.