A writer is, before anything else, a reader. The clearer your reading, the clearer your writing. What follows is the analytic method I would have taught you for each genre.
The first reading of a poem should be aloud. A poem is a piece of music as much as a piece of writing, and you cannot hear it until you have said it.
The reader of a memoir is always listening for two voices. The voice of the person who lived through the events, and the voice of the person who is now telling about them. Mark, with two different colors of pen, the lines that belong to the lived self and the lines that belong to the telling self.
Beneath the differences between the genres there is a single reading practice. I call it close reading, but it is also just reading the way you would listen to a friend. Six steps.