Comment by iamflimflam1

I will tend to do make the schematic. I’ll use labels for most connections from the mcu to any peripherals.

On the PCB, the most critical thing to my mind, is component placement. I’ll do that before any wiring up and then use that to determine the most sensible GPIO pins to use.

For the routing I’ll modify the pins used to make it easier/simpler.

It’s definitely an iterative process with a lot of back and forth between schematic and PCB.

The nice thing with the flexibility of the GPIOs is that I don’t need to do much upfront design. I’ll just label pins up in the schematic and if needed tear it up and redo.

The real trick in the schematic is not “wiring” all the connections up. Just use labels that are easy to move around.