While at Walgreens today, I came across a product called “Neat Sheet.” Why use your old towels and blankets at the beach, when you could use a sheet that is specially formulated for the sand and water?
Brilliant. Think of an item where you already own, but that you use it for something else.
Now that take that function and develop a product that is specially formulated for that function.
Get the idea? Be a millionaire.