Inspiration to get your creativity rolling is all around you. All you need to do is cultivate the 'What if' question.
Maybe you're reading a short story about a history professor and an actress on the topic of kick-boxing or orchid growing. You might think to yourself - what if that's not a history professor but a salesman, not an actress but a young girl and instead of kick-boxing or orchids the subject is homelessness*. What might your creativity come up with given these different characters and different situation?
Or you might be studying a picture, photo or painting of a summer's day landscape of a lake surrounded by trees with mountains in the background, all in shades of green with a blue sky and fluffy white clouds floating around. What if it were autumn? How would the colors change on the trees (which would also change their reflections in the lake); what color would the sky be; what color the far hills? Think of these things and another great painting will be eager to leap from your brush.
One of my favorite materials is polymer clay. It's so versatile and there are so many different techniques you can try out with it, all leading to differing results. But, what if that were marzipan or sugar paste and you had a birthday cake to decorate?
For example, the decoration for this cake was created from hours of practice using polymer clay - it's not a professional finish, but the birthday girl was pleased with it... (she's a keen gardener and flower lover)
Ideas in one area of creativity lead to ideas in others and as the ideas lead, the confidence follows. Once the confidence in your creativity grows there'll be no stopping you!
*You can read the story mentioned above about the salesman, the young girl and homelessness here. It was one of my first short stories to be published and I'm still fond of it.