I used to get coder's block, which is like writer's block, only for software. I'd stare at an empty screen, having no idea where to start. I'd dither between two implementation directions, unwilling to commit to either course, while the cursor blinked away the seconds in the corner of that empty screen.
I cured my coder's block, by the same technique recommended to cure writer's block; write something.
OK, initially this is hard advice to follow. By definition, if I didn't know what to write, what could I write? If I didn't know which implementation path was best, wouldn't I potentially be wasting my effort writing the wrong thing?
The solution that worked for me was to write something different. If I didn't know what code to write, I would write down a list of requirements (in prose) for the code. If I was looking at a big undefined area and I didn't know just what I'd need, I would write a structured walkthrough, again in prose. Or, I would write the function header, so that what I was doing had a name and an argument list and a return value. If I was feeling particularly virtuous, I would write a module test attempting to use the unwritten method to solve the problem.
And this is what happened. As soon as there was something on the screen, I could begin to review it. I might realize that I didn't know what the requirements were. That gave me something to think about, and pretty soon I did know. If I did a walkthrough, I would find myself writing in the passive voice, which would mean that I didn't know what object called which method. Now I had a hook on which to hang further thought. If I wrote the function name, I could begin to think about whether I really needed to do a thing with that name. Every word I wrote got thoughts out of the nebulous fog inside my skull and down in (temporarily) solid and immutable text where I could see it and analyze it and refine it.
If I couldn't write a paragraph, I'd write a bullet list. If I couldn't write a bullet list, I'd write a few conceptual phrases. What I would not do is get a cup of coffee or read my email or surf the web. That way lay madness. OK, maybe just a little surfing, but I would hold it in mind that I was procrastinating, and what I needed to do was to grind it out.
I know some people who deliberately distract themselves with some email or web surfing. Maybe that works for them, or maybe they are self-deluded. But for me doing something else is just postponing the hard stuff. I know some people who say the answer comes to them in a dream. In my dreams I just worry about being blocked, although sometimes in the morning I have amazing insights in the shower, when I'm very fresh.
When I grind it out, I almost never find I've gone down the wrong road. Perhaps that's part of being an Old Hand. Come to think of it, I conquored my coder's block about the same time I became an Old Hand.