Keep a small tablet handy. It isn't the billions of ideas, that pop up in the minds of humans around the globe that make money. Very few ideas are worth the time it took for the thought. Of the ideas that are good, very few are followed up and ever end up as a worthwhile development in the market place. Most people are just not oriented to do anything about their ideas, while others believe it would take too much of their time and money to follow through to completion.
Most inventions are merely new arrangements of things that have already been invented.
Alter or improve in any number of different ways something that already exists. What you dream up can be your key to great wealth. Ideas for improvements are one of the most valuable things you can contribute to society and at the same time add to your bank account. To create ideas for improvements, consider every possibility and alternative for the thing you want to improve. Learn to create ideas by evaluating all the different aspects of the product, method or concept you are interested in.