Synonym Savvy is a companion text to Dictionary of American English Idioms and Slang, also by J.D. Hunter. It will give you the tools to unlock an ordinary American English word such as "advantage" and enhance it by using an idiom or slang word/phrase having identical meaning. For example: "Get a leg up", "Beat him to the punch", "Ace him out", "Make hay while the sun shines", "Strike while the iron is hot", Have someone over a barrel" all mean "Having an advantage".
This book will greatly enhance your conversational abilities, especially if you are an ESL student. It sells for $35.00.