INFP here. When I tackle a creative project, it definitely comes from inspiration of some sort. I get this mental picture of it in my head, and then I begin to uncover it through whatever medium I'm working on, though I mainly sculpt. When truly inspired, it's almost as if I am just a conduit rather than a creator. In those situations, I am like a mad woman, working on it tirelessly till its completion. When it's finished, I usually have a very feely moment that brings me to tears, like giving birth to something. Of course most of the time I'm so pessimistic about it's outcome and feel like I failed the vision that had inspired me to do it in the first place, but I am extremely fulfilled in that I finished it, brought it to life.
My INTJ husband approaches any project, whether that be creative or otherwise, in a very methodical way. Like he has it all mapped out first and never deviates from his plan of attack. It's not a rush for him to complete as it is mine, but he'll work on it daily till it is finished. When it is, he often expresses relief, as in a "Thank goodness that's over with!" fashion, even if it was for his own enjoyment. He also expresses that he is fulfilled, or rather, satisfied when whatever it is has some sort of purpose. Mine usually serve no purpose at all, sometimes decorative, but it's more of a need for me to get it out from my head and into the real world. His... it
must have a practical use or else it is meaningless.
Examples would be a sculpture of a human form I completed, that is now in storage because it creeps my kids out..

VS a bookshelf he made with his own bare hands. Not because he really felt the need to work with his hands and feel the wood beneath his fingertips, but because he had a box of books. He had power tools in the garage. Why buy one when he can make one?
Hope this helped!