I'm interested in hearing how do you prepare for the jam? Do you for example create some boilerplate code to save time during the jam? Do you practice?

I usually prepare for the jam by opening Unity and doing some initial testing few weeks before the jam. For example now I am very interested in doing some hex-based strategy game, so I have been doing some initial testing how the unity tile-maps work etc. I have never used the Unity tilemaps before and I dont want to spend the whole jam learning it. I have also already implemented some basic path finding algorithm that I plan to use during the jam, as the rules allow to use ANY previously done code.

What about you guys? How do you prepare? And do you think it is ok to start coding before the jam has started?