Once you’ve fixed something, the next step is to take something apart that’s not broken, so you can make it adapt to your personality, instead of you having to adapt to it’s designer’s guess of your personality.
It doesn’t have to be all-encompassing or complex. Depending on your field of innovation, it could be as simple as relabeling a few controls.
If you’re handy with a soldering iron, it might be replacing red “on” lights and LEDs with a green one (red should be used only for error signals and other conditions that require immediate attention).
The next step up would be installing a ready-made upgrade kit, such as the Tweet-a-Watt.
But don’t limit yourself to adding features. Sometimes a product can be made better by removing less-useful and less-often used features.
Next up would be building a new feature from an Arduino board, or something similar.
The primary goal is to figure out what could have been added (or subtracted) from the original design to make it better, easier to use, or sell more.
But a secondary goal is to demonstrate to yourself that you have knowledge and design instinct that is, at least in some areas, equal to or superior to that of the product’s professional designer. With this realization and confidence, you will be able to innovate more often, and likely more deeply.