“In the beginning, God created….” (Genesis 1:1)
Real creativity is a God thing.
When you sit down to write or draw or whatever, remember that your Muse (the Spirit of God, the Original Muse!) has read it all and seen it all and inspired much of it, so He is your greatest Resource.
Those who want to learn to write should surround themselves with good writing (i.e., excellent reading material) and get to know inspired writers.
Those who want to think creatively should occasionally plant themselves among off-the-wall thinkers, people whose minds push the boundaries in every direction. They will loosen you up.
And then, pull back and spend a lot of time alone, thinking.
Go to bed thinking about whatever is bugging you, inspiring you, burdening you, pestering you, charming you, or puzzling you. Your subconscious will keep at it while you recuperate.
If something occurs to you in the middle of the night, you absolutely must get up then and write it down. If you plead that you are sleep deprived and insist that “this is such a great insight, I’ll surely remember it in the morning,” the single thing I can guarantee is that you will not remember it when the night is over. Iron-clad promise.
You must get up when the idea occurs. Write it down.
I am not suggesting you should live with the people whose minds are all over the place, whose thinking knows no limits, who challenge everything. Do this and you will soon lose touch with reality.
Just once in a while, associate with free-thinkers.