Here is a whole page of line drawings you can use to sharpen your memory. These are meant to help you learn to keep details in mind over extended periods of time, and recall details later. To use these, pick one you want to memorize — click on it, so it’s the only thing you see on the screen. You can also print it out. Study it for a while, and you may also want to practice drawing it.
After a few minutes, go do something completely different. Check your email. Or eat a good meal.
Later, get some paper and a pencil and see if you can remember how to draw the image.
Try again several times a day — and over the course of a few days. See if it makes a difference for you. I know it does for me.