Yes there are definitely structures in my life - I live within the bounds of project deadlines.
However within those bounds, I try to do those things that come easiest - that is, those things where I have the confidence to say that I see a possible solution. I avoid forcing myself to do something where I do not have the feeling of having an approach/solution/idea.
Instead I do something else and 99 times out of 100, an idea pops up and I return to the original activity/task/project. However there is no time limit when this will happen. And that is the unplannable part of my approach. I do stick to deadlines by delivering what has been done and having good excuses for those that have not - delivering on time is more important the completion.
I try to stay busy with tasks so things do get done and loose-ends are tired up. Something is always completed and with it, progress is made.
On the other hand, when I have no ideas, a moment of silent meditation/power-napping/slumber helps to calm the mind. As I get older, I have come to realise that planning is necessary but shouldn't dominate. Calming the mind and emptying it helps my unconscious to catchup, i.e, reorginise, restructure and plan but an unconscious plan.
There is no guarantee that the approach I take will work, in many cases, I make a learning that a particular approach was not a good idea! But that then becomes the result: to have made the learning and do it better/differently the next time.
Important is also to stay positive and never forget to see the positive learnings from attempts that fail. That is the hard part: be prepared to fail and learn from that. I try not to be hard on myself for perhaps taking the wrong approach - hindsight is 100%, everything else is guesswork.
Within the bounds of a project, what I'm describing is nothing more than explorative solution identification - i.e., from point A, we want to get to point B but have no correct or defined path to take. So how to find the correct path? I don't know and a random or "unconscious" approach is as good as anything else - with the assurance of not going around in circles by maintaining good documentation (for me that's a 2 dimensional mind map).