Packaging items together to create a unique item is a terrific way to position your business away from others with similar products.
While other retailers may sell journals, erasers, pencils, rules and similar products. Only you might have the items in a package under a name you created. The photo shows how a premium stationery brand does this.
You can create a unique package with what you have in your shop today. You could package together based on function, colour, brand or more.
For what it is worth, I think packaging by colour is a good starting point.