I am the same. I'll just fiddle around with boilerplate code or procrastinate off other tasks, but that is only semi-consciously. What I am really doing with like 60% of my focus is trying out different designs/architectures around a problem. This might take a few days until I figure out a design that fits the task, but once I'm satisfied, it's usually only a few hours to code the thing.

Worth noting, this process can be significantly sped up if you have a set of peers (or smarter) people to discuss with.