I belive most of you lay out some ideas on paper first: levels, designs, math calculations. For me, these are one of the most adorable parts of game development (I still have on me my very first paper with code testing for first game from 10 years ago).

Would be very interesting to look at your sketches and chaotic calculations for this gamejam :D

Here are mine:

And here is the finished product (sped up for convenience):

(You can play my little arcade puzzle DETOUR here: https://ldjam.com/events/ludum-dare/53/detour )