Take out a piece of paper and a writing utensil. Begin writing down a series of random numbers on the paper. The exact makeup of those numbers is not relevant, just be sure that there is no pattern being applied to them. Once the numbers are recorded, examine the series of numbers, starting at the beginning. Try to remember as many of them in order as possible. On a separate sheet of paper, begin recording those numbers as you remember them, writing down as many as possible. Then compare to original sheet with the second to see how well they match up.
As with the random numbers exercise, write down a series of random letters on a piece of paper. Again, take care to not apply any pattern to the letter, or spell any words with them. Once completed, again study the sequence of letters, trying to commit to memory the exact order. Write down your recollection on a separate sheet of paper, and then compare the results to the original.
This memory test requires a deck of playing cards. Shuffle the deck. Begin laying down the cards, one by one, face up. Try to remember the order of the cards as they are placed on the table. After laying down a number of cards, pick up the cards now laying face up on the table, and then turn them so they are face down in your hand. Try to predict the order of the cards as they are again placed on the table.
This test requires two sets of playing cards. Lay down each card in the two decks individually on a table, making sure there is a separation between the two decks so the cards can be kept straight. Then, begin flipping over one card from each deck, one by one. If a pair of cards flipped over match --- such as the ace of spades from one deck being matched with the ace of spades in the other --- remove those two cards from the table. If the pair of cards do not match, flip them back over and continue searching for more matches until all cards are matched.