@Blenster what software do you use? How well does it auto route?

@Blenster Reset button and power switch (or a couple of pads you can jumper or use for a power switch).

If you have power or status LEDs use high value resistors to keep them dim and efficient, 4.7k is fine.

Make sure your connectors face the OUTSIDE EDGE of the PCB, the silkscreen might be confusing.

If you have pluggable headers check the plug side for anything that descends below the PCB surface.

Your breakaway/mousebite needs 1/3 the remaining material your instincts demand.

@Blenster There's also https://github.com/azonenberg/pcb-checklist from @azonenberg

@Blenster Some brilliant tips here.

This made me laugh and then "oh yeah, hadn't thought of that" :)

"Are there stray antenna-like features to the copper?
e.g. Planes that got sliced by a trace and have a connection only on one end"

@Blenster thanks, these are awesome!

@Blenster great list!

@Blenster i would add one thing: if you have screw-terminals or sd-card slots: check if they are oriented the right way (often you do not have 3D models for the exact part…) on my last design i exchanged the sd slot for another model because the original was on backorder… the replacement had the pins at the front instead of at the back… so now the sd card is more of “fixed flash” than actually exchangeable 😝