I'm not much of a poet, but I did get stumped just like you in my creative writing class. My teacher suggested finding an everyday object (like, say... a glass of orange juice), think of some traits it has (it's cold, refreshing, smooth, a jumpstart to someone's morning), and try comparing that to some tone or feeling. In fact, you wouldn't even need to mention any sort of feeling if you keep the same tone and use similar tone words throughout the poem 'cause the message will be clear by the end.
But, heh, I'm not a poet, so there's bound to be other members who'll come by and give better advice. Though what I said did give me perfect scores on my poems in class, so maybe there's potential? XD
EDIT: Feel free to use the glass of orange juice if you so wish!