A pair of psychologists have some advice for remembering important items on your to-do list. Learn to associate the thing you’re trying to remember to do (such as grabbing an envelope you need to mail on your way out the door) with another cue, such as the smell of the flowers on your desk or the sight of a string tied around your finger

In a study published in Psychological Science, Todd Rogers and Katherine Milkman of Harvard University and the University of Pennsylvania find that it’s easier to remember to do something if you use a clue that you’ll encounter when you need the memory to surface—such as reminding yourself that you need to get a flu shot when you start seeing Halloween candy in stores. This method can be even more effective than writing a reminder note, the authors found. 

The study tested this hypothesis over the course of five experiments. In one trial, 87 students were told that the study would donate $1 to a food bank if they remembered to pick up a paper clip when they were given their compensation for the study. Some were told that there would be an elephant statue on the table where they were picking up the money. Almost 75 percent of the students in the elephant group remembered to take the paper clip, compared to 42 percent of the control group. A different experiment found that when coffee shop customers were told that a stuffed toy would be on the counter to remind them to use a $1-off coupon, 24 percent of customers who took the coupon remembered to use it, compared to 17 percent of the group who received a coupon without the stuffed toy reminder. 

Another trial found that it was important that the clue was obvious and distinctive compared to everything else around it. An image of one of the aliens from Toy Story worked better as a reminder than a written reminder when it was surrounded by other text. 

So basically, to remember more of your must-do tasks, put pictures of aliens all over your house.