Asymmetrical : having parts that fail to correspond to one another in shape, size, or arrangement.
Let's literally go with KEYS! They are a common enough item and one we all probably have too many of. I tend to hang on to keys. I have an assortment of keys, some of which I no longer even know what they are meant to unlock!
Find some keys and see if you can photograph them asymmetrically by size, colour, or arrangement.