The memory palace, and other memory techniques, are a set of tricks that dramatically improve your memory on specific tasks. 
The key insight is that our memory works best spatially, with vivid images, and when related to other knowledge you already have.
Let's say you're tasked with buying beach supplies for a group of friends. You just need to remember 3 simple things: a beach ball, sun screen, and some beach towels.
- Think about being in a familiar place, like the front door of your home.
- Imagine a vivid object you want to remember here, like a life-sized giant beach ball at your front door.
- Create a path through this place with objects along the way. Walk through the door of your house, where a bathtub full of sunscreen sits in your living room. You continue to walk to the kitchen, where a naked person stands wrapped in a towel.
- Trace back this path to remember the list.
You should now easily have come to mind a beach ball at your front door, a bathtub of suncreen in the living room, and a naked person wrapped in a towel in your kitchen. Just trace back through this whenever you want to make sure you bought all of the right supplies.
This technique can be used to memorize thousands of items. The world record holders for Pi digit memorization have passed 70,000 digits memorized. Let's hope you use that memory for something a bit more useful...
- The more vivid the objects are, the easier they'll be to remember. A common trick is to use something exaggerated, detailed, funny, sexual, gross, or otherwise memorable.
- When faced with abstract words, like e-mail, use something related and more concrete to help remember. For e-mail this could be a mailbox... or a she-male.
- You can draw from any path or building you know well for creating memory palaces.
- You can also create imaginary rooms & buildings. You can use distinctive colors and architectural styles to make them feel more real.
- Tracing back your path mentally will improve its recall.
Elaborative encoding is the basis of most memory tricks. It means that you best "encode", or store, your memories with a rich mental association. The more elaborate, detailed, and visceral, the better!
There are many ways to apply this concept. The Major system involves assigning a sound to every number. The memory palace involves assigning a place and image to each item.
Learning, in and out of school, is improved with these techniques. When learning abstract concepts, you can use locations, vivid imagery, and relations to help integrate the information and better recall it.
Using this trick results in a statistically significant increase on test scores because of it's effectiveness in allowing you to remember more information in less time. 
You use can these techniques to better remember:
- Talking points for speeches, meetings, etc.
- To-do lists & shopping lists
- Information about people you've met, like their names, interests, birth-dates, etc.
- Foer, J. (2011). Moonwalking with Einstein: The art and science of remembering everything. New York: Penguin Press. https://www.amazon.com/Moonwalking-Einstein-Science-Remembering-Everything/dp/0143120530
- Qureshi A, Rizvi F, Syed A, Shahid A, Manzoor H. The method of loci as a mnemonic device to facilitate learning in endocrinology leads to improvement in student performance as measured by assessments. Adv Physiol Educ. 2014;38(2):140–144. doi:10.1152/advan.00092.2013