On a whim, I recently picked up a little paperback volume on Proverbs by William Mouser published in 1983. I have to admit I have enjoyed working through parts of this book. It is clear and concise. One example is the following statement which I found both simple but helpful.
"All the major figures of speech you will encounter in the proverbs of Solomon operate according to one of two devices" comparison and substitution."
Mouser goes on to note that the comparative devices in Proverbs are similes, metaphors, and hypocatastasis. The substitutionary devices involve synechdoches and metonymies.
William E. Mouser, Jr., Walking in Wisdom: Studying the Proverbs of Solomon (Downers Grove, IL: InterVarsity, 1983), 101.