Rollo May talks about form in The Courage To Create. Years ago when I was a poet I studied and experimented with form. Sometimes the idea I was trying to express fit into a particular form and sometimes it didn't. That didn't mean the form was wrong. Not all words flow into a sonet or a couplet or any other specific form. Sometimes the words gushed out and later the form was found. Then I turned to fiction and discovered there were forms there.
There's the beginning, the middle and the end. Most literary works fall into this pattern. What makes it creative is how the writer uses this general form. Lots of times writers experiment, and not all these experiments work. The discovery is what makes creating fun.
There is joy when the right form to express the words, meaning, feelings we want to show the world. While I had fun with poetry, and dabbled in creating music, played with short stories. Writing novels was the form I really gravitated to. So now I have fun finding the form to put my thoughts and meanings into.
What about you? Have you found that form aids your creativity?