1. Symbol
A symbol is something which represents an idea, a physical entity or a process but is distinct from it. The purpose of a symbol is to communicate meaning. For example, a red octagon may be a symbol for "STOP".

2. Symbol - 2
A symbol of Freedom? Or just a bird?

3. Symbol 3
Light and Dark - symbolizing good vs. evil? Names of characters - representative of some aspect of the character's personality/destiny

4. Symbol 4
Familiarize yourself with the author's work and style. A symbol in a piece of literature often represents an important issue of the time in which the author lived, or has personal significance to the writer. Edgar Allan Poe, for example, is well-known for the tragedy he suffered during his lifetime. His stories and poetry often included dark imagery and death which were undoubtedly symbolic of the events in his life.