Practice exam questions so you know what you are doing and what you need to know.
Use mark schemes and listen to Bruff and Salles.
you can make flashcards on the poem in general or perhaps a mindmap of key themes, context and techniques used including structure.
but the most important thing is to get used to making poetry comparisons. do plenty of practice whether that be timed essays in exam conditions or essay plans- you need to be able to make coherent connections between poems and compare them, not just describe each of them separately. the more exam practice you do the better you'll get at comparing them you can easily make up practice questions of your own or if you're aqa there's a poetry guide in the stickies on power and conflict.
mrbruff and mr salles are both very useful for poetry, i'd recommend watching a few of their videos if you get stuck.