I did my JC last year, got an A in English so I suppose I might be of some help, poetry has always been my favorite section by far, I personally find it really easy to come up with stuff to write
I learned a good few poems but I didnt go overboard learning a lot of info about them, they were more like backups, and then I learned one extremely in depth that I planned to try and make work for the question :L
The poems I did: (keep in mind, I didnt learn these ones in much detail, I had them just in case a crazy specific question came up that didnt suit the one I did in detail :L, hence why I have so many
Dulce et Decorum est
When You are Old
The Road Not Taken
The Lake Isle of Inisfree
Shall I compare thee
The Thickness of Ice
I made sure I knew one war, one love, two by the same poet, two with the same theme, and then a few miscellaneous ones like ones with good imagery, death/grief, descisions etc, for the more obscure questions :L
Then I learned 'He wishes for the cloths of heaven' in like craaazyy detail, I love the poem and know it off by heart, and I'd always always used it for poetry answers, so I was counting on it to get me full marks :L
When making notes on poems I usually make them under the headings 'Summary', 'Imagery', 'Techniques' (assonance, alliteration etc.), and 'Quotes', and Id usually do it in bullet points
As well as that I made out little flash cards with quotes written on one side and a 'hint' on the other side, to help me learn the quotes.
When writing an answer for poetry I'd usually do a short introduction paragraph, just giving a short summary of the poem, then Id do a paragraph addressing the question, for example if it asked about a love poem, Id explain why I consider it a love poem, then in the following paragraphs I'd expand on any points I had made in the previous paragrapy, usually in the 3rd paragraph I write about the techniques used, and in the 4th Id write about the imagery, but make sure to always relate back to the question! Then at the end Id put a short paragraph about what I personally think of the poem etc.
Hope this is of some use to you