I typically keep some space in the recall column to write down associated PAO, Major System, etc. images related to the key concepts, dates, and other notes and sometimes include locations along with the images. Sometimes I may make the notes themselves the memory palace by drawing sketches, doodles or other drolleries into the margins. Depending on the information I may also encode details into other pre-existing palaces.
I can then come back to the notes and do spaced repetition over them to strengthen the images, loci, and ideas. Depending on the material, I might transfer the basics of the notes over to Anki or Mnemosyne for more formal spaced review.