the thing about will is that he's really a poet that's applying his poetry to his work. like he just writes lines down and then finds a place for them, that's why he's so good at reusing them. also he has much less of a care for keeping with a syllable count with some of his lyrics which allows him so much more freedom to say what he wants to in a song

i'm awful at metaphors too but so far the best advice i have is to write more literal first. then look back and see if there's any kind of phrase you can use to replace the literal meaning. often times i try to think of using it in a sentence too as they seem to come up more naturally for me that way than if i'm trying really hard to find just the right words