Yes, I still have self-imposed limitations when I get ready to FMQ. I recently worked on a desk runner for my hubby and when I first started I was almost paralyzed to do anything past STID. DH hinted that he would really like to have it at his desk and I gave myself a push and just started doing it. No marking, just free-form with contrasting thread. It turned out great. Are the patterns even? NO. Are they consistent? Not really. Can anyone tell by just looking at it? No. He had so many compliments and some of his colleagues told him that they want to buy one from me. That is quite a compliment for a completely scrappy project.
I do spend a lot more time preparing and planning the FMQ path. I do it with pencil on paper. Not necessarily to scale but enough to give me muscle memory from repeating the patterns. It makes such a big difference.