I have a Dilbert cartoon which has Dilbert looking at his PC and becoming distracted by more exciting activities. The caption reads "I have met the enemy, it is ourselves" In effect it means we defeat ourselves. In a creativity sense we often just 'leave that to the bright sparks'. This is both foolish and an incorrect perspective.
Sure some people have more ideas and find this process easier. Here's a simple thinking tool to get you started. Many of us have heard of the '3rd Way' or, a third/new alternative. Many of us are too linear (your way, or my way...you win or I win) In fact, the idea of 'win/win' is in itself creative. It's a 3rd way that's better than we can achieve on our own.
Look for more win-wins, it will free up your thinking and that flexibility will allow new ideas and possibilities enter your consciousness. The rest is practice and learning!
Our egos and fear of making a mistake confine our thinking unnecessarily. As our own Beckett famously once said; "Fail, fail again, fail better". This encourages us to take some risks but we must also take the time to learn from what's happened..........Have fun, small wonder young kids are so creative! Try asking for forgiveness instead of permission and see what happens! Got to be at least worth a try! Let me know how you get on.