I will often do this when I am drawing a blank. Write psuedo-code, or code that is how you would like it to be, if your language / macros / libraries supported it. Then you can worry later about making your language support what you just wrote. This eliminates a whole set of mental blocks to writing code.

I don't write anything longer than a page or two of script, but sometimes I'll walk away from the computer and scribe psuedocode onto a few sheets of paper, because I'm talented enough at becoming perplexed to be able to do it in that short a script.