Look at a piece of information that you need to remember, such as a sequence of numbers or letters. For example, you might have a password like "DGUICTNDIPOR" that you need to memorize. However, since your short-term memory is limited to four to seven items, this sequence of letters will exceed your capacity to temporarily memorize it.
Mentally divide the sequence of letters into separate sets of three letters each. In the above example, this will lead to four chunks, specifically DGU, ICT, NDI and POR.
Memorize each of these chunks in this order. Because your brain now sees these letters as four items, you should be able to memorize the sequence.