If you have a long list of things to remember, such as a shopping list, the peg system is an excellent memory technique. It's similar to the memory palace method, but instead of attaching information to geographical locations or rooms, you use a list of rhyming or alphabetical pegs.
Wikipedia offers this rhyming example:
1-gun visualise the first item being fired from a gun
2-zoo visualise an association between the second thing and a zoo
3-tree visualise the third item growing from a tree
4-door visualise the 4th item associated with a door
5-hive visualise the fifth item associated with a hive or with bees
6-bricks visualise the sixth item associated with bricks
7-heaven visualise the seventh item associated with heaven
8-plate visualise the 8th item on a plate as if it is food
9-wine visualise a glass containing the 9th item
10-hen visualise the 10th item associated with a chicken.
For example to remember the following grocery list of 10 items:
Apple: Picture an apple being fired from a gun
Butter: picture a gorilla stomping up and down on a stick of butter
Razor Blades: Picture a tree with razor blades for leaves
Soap: Picture a door made from soap
Bread: Picture bees flying from a loaf of bread as if it is a hive
Milk: Picture a brick house with milk jugs where the bricks should be
Cat food: Picture an open can of cat food with angel wings and a halo
Bacon: Picture bacon on a plate
Batteries: Picture a wine glass filled with batteries
Orange juice: Picture a hen being squeezed, and orange juice coming out
Although it takes a while to learn your peg list, one advantage of this system is you can create an unlimited number of pegs (this site lists 1000 pegs). You can use shapes instead of number rhymes to set up your system. For example, imagine the 1 is a flagpole.
If you can memorise images for all numbers from 0 to 99, you will have a powerful system used by memory champions.
Check out Peglist.com, which builds visuals for you of four items in a list using the 1-gun, 2-zoo, 3-tree and 4-door associations. Then try creating your own absurd and easy-to-remember imagery.