This text is from " DEveloping Skills for the TOEFL iBT" written by Paul Edmunds and Nancie McKinnon.
Research shows that people can improve their memory if they creat an image of an item in their minds.For example, say a person needs to buy a blanket and a teddy bear at the store. The person first combines these two items in his mind. He imagines the teddy bear that he will buy for his nephew wrapped in the blanket. The key point is creat a mental image with all of the items one wants to remember together. This groups the information (images), so recall becomes easier. Assigning colors to the objest is also helpful. So, now his nephew’s brown bear is wrapped in a yellow blanket. Alternatively, the yellow bear is wrapped in a brown blanket. Researchers have found that the use of such creative tricks significantly improves memory.