First of all, find a simple subject to photograph. The classic artist's choice of an egg is actually a brilliant option as you can do so much with it, but you can use any object such as a lemon, a bottle, a fork and so on. Just make sure it's a simple, everyday object.
2) START WITH 5 DIFFERENT PHOTOS Focus on... LIGHT - COMPOSTION - TEXTURE
The challenge is then to take 10 completely different photographs of your subject. Think about using light, compositional techniques, adding depth, or using color and texture to add interest to your subject for the first 5 photos.
3) PLAY
Then next 5 photos have some fun. Feel free to play around with your subject - for example with a lemon, slice it and photograph the inside, or for eggs, crack the shells and photograph the contents or the shells themselves. You could also add other elements into the scene, or change out the background, or move the item to a different location. Remember, there are no rules as such with this exercise - if you want to make it harder, impose some - for example, keeping to the same location.