Literally just going through each one and writing notes about different quotes / techniques /ideas helps quotes stick in your memory. You could listen to them on youtube or spotify. I'm learning 4 of the easier ones like London, but you don't have to. As long as you know like 6 poems in detail that cover all the themes, and perhaps 3 quotes from the others to cover yourself. Learn 2 or 3 bits of context for every poem, know who the poets are and when they wrote (I'm pretty sure time counts as context, though I'm not sure). Shmoop and Genius are quite good for analysis. I'm doing eduqas, so perhaps some of that is irrelevent. I was really worried too, but I've realised I actually know them a lot better than I thought after just reading them and thinking about them.
For example, I do AQA Love and Relationships so I would split them into themes like: