Before the invention of writing or electronics, people used to keep palaces devoted to memory. Not physical palaces, but mental ones!
1. Think of a place you know well… a childhood home, perhaps, or where you live now.
2. Imagine walking up to that place, and putting the first object to remember right on the front porch.
3. Then, step inside and turn to your left. What do you see? Put the second object there, and so on.
The items would be remembered when you mentally visited the place after a while.