a metaphor for macaroni salad
http://www.tnellen.com/cybereng/lit_terms/terms/2terms.html#Metaphor
http://www.tnellen.com/cybereng/lit_terms/metaphor.html
http://web.cn.edu/kwheeler/lit_terms_M.html
(Scroll down.)
Read the definitions and examples. Then write what you think is a good metaphor, and someone here will give you feedback.
=)