If you think of metaphor as comparing two unlike things where one equals or is the other without using the words like or as, and then hold one unlike thing in each hand to make sure you really do have two unlike things to compare, metaphor will be easier. For example, in the Queen Mab speech, Mercutio says that, "her chariot is an empty hazelnut" which is a metaphor comparing her chariot to an empty hazelnut. You have two objects which are unlike each other saying that one IS the other rather than like each other which is what a simile does. Another example in the same speech is a bit more subtle because the word "is" is not used but implied. "Her whip of cricket bone" or even "her wagoner a small gray-coated gnat" are both implied metaphors comparing two unlike objects,the whip with the cricket bone or the wagoner with the gnat, without using the words like or as. Many more metaphors are in this speech which you can find if you remember the definition and find the two objects to hold in each hand as you compare. Obviously, holding the objects in your hand is not a literal direction, but it will help you figure out metaphors.