You need to have more ideas bad before you can have more good ideas.
That’s it. If you feel like you’re not creative, it’s simply because you’re afraid of having bad ideas. There’s no such thing as creative and not creative people. There are just some people who are willing to have bad ideas and some people who are not.
Normally, an idea arises, and we immediately label it as “bad,” or “silly.” What does this tell our minds to do subconsciously? Stop having ideas! When this happens, we start to view ourselves as “not creatives.” So we stop thinking about ideas and leave that job up to someone else.
Bad ideas are just a fact of creativity and brainstorming. Most of them are going to be bad, but you have to get through the bad ones before you can get to the truly good ones. You first idea is never your best. Push past settling for one idea and try to come up with twenty. Even if 19 of them suck. All that matters is that you find one good one.
To have more ideas you need to have more bad ones. Practice that principle and you will become more creative.