One way to allow the Holy Spirit freedom to partner with you creatively is to acknowledge your God-given imagination and dedicate it to the Him. You use your imagination all the time. If you hear the word "bicycle" you instantly get an image in your mind's eye. You have thousands of stored images to draw from-maybe you visualized the bike you had as a kid, the one you own now, or the one you wish you could buy.
What if you hear this: a red bicycle with a wicker basket full of daisies tied to the front handlebars? Could you visualize that? You're using your imagination, which was given to you by God to enhance your life here on planet earth.
Once you make friends with the idea that God gave you an imagination, you're well on your way to Holy Spirit-inspired creating. Take some time to dedicate your imagination to the Lord. Ask Him to fill it with thoughts, ideas and pictures. The Bible is full of examples of God using pictures, visions, dreams, stories and out-of-the-box ideas to communicate to His people.
Dedicating your imagination to the Lord is just a start. Another simple thing you can do is listen to worship music while you create. This encourages an atmosphere where you focus on the goodness of the Lord. Sit with your eyes closed and meditate on the words to of a worship song. Write out a prayer as you listen to the music. Try drawing or painting (even abstractly) in response to what you're hearing. Let the music set the tone and you might be surprised at what you end up creating.
Don't be afraid to start small. Not every work of art has to be the equivalent to the Sistine Chapel to be important. Maybe it's a journal entry nobody but you will read, or a small sketch on a scrap of paper that stays hidden away. Don't judge the outcome. Just as it took you years of trial and error to learn to read or write, so it takes practice to partner with the Holy Spirit in new, creative ways.
If you make it a practice to invite the Holy Spirit to your creative times, your confidence and comfort level will grow, as will the depth and richness of your relationship with the Lord. Give yourself permission to be a student and to try new things. And give the Holy Spirit permission to join you in your creative adventures. You won't be disappointed.