The memory palace is not a gimmick

The story is that Simonides of Ceos walked out of a banquet hall shortly before the roof came down, and was able to identify the dead by remembering where each guest had been sitting. Whether or not that happened, the observation underneath it is solid: you have an enormous, effortless memory for places, and almost none for lists.

The method of loci borrows the first to carry the second. You take a route you already know, you place things along it, and you walk it.

Building one, properly

1. Pick a route you could walk blindfolded. Your home is the obvious one. A route through a school, a shop or a game you have played a lot works just as well.
2. Fix the stops in order. Front door, hall, kitchen sink, fridge, sofa, television. Between eight and twelve is right for a first one. Walk it once in your head and make sure the order never wobbles.
3. Put one thing at each stop. One, not two. The stop is the address and an address with two houses on it is not an address.
4. Make it interact with the stop. Not standing next to the fridge. Inside the fridge, freezing, with the door refusing to shut.
5. Walk the route, do not scan the list. The order is the retrieval mechanism. Walking it forwards and then backwards is the fastest way to find the stop you rushed.

What it is good for, and what it is not

Palaces are unbeatable for ordered material that has to come back as a set: the ten most common verbs, a set of endings, the days of the week, a sequence of steps. They are unnecessary for individual vocabulary, because a keyword hook plus a scheduler already handles that and it handles it with far less setup.

The trap is building a palace for everything. Fifty rooms of vocabulary is a lot of construction work that a review queue would have done for you while you were on the bus.

Re-using a palace

You can, and it works better than people expect. The old contents fade fast once you stop walking the route with them in it, and the stops themselves do not wear out. Give it a couple of weeks between uses and be prepared for one or two ghosts from the previous set.