My very first ever mistake was not knowing that capacitors have pin numbers assigned to polarity. This did not affect the function of the board, but the silkscreen showed the opposite polarity.
My last Pcb misteaks:
In a self-created SOT-23 footprint, the footprint had one of the pads not centered exactly right; the pad was within tolerance and still worked. Note: This might be due to the old nightly version I have.
The SOT-23 part was an N-Mosfet. I should have learned from my prior board, that pin numbers matter. I used the pin numbers for the same part in a TO-220 package… DOH! The symbol name, DGS or GDS is important as this should correlate with the pin numbers of the package. As in D-pin1, G-pin2, S-pin3 vs G-pin1, D-pin2, and S-pin3.
Note: Maybe the quirky pad placement allowed me to remove the part and solder it back in 270 degrees counterclockwise and still have a usable prototype board!
My design uses interlocking terminal screws. The footprints are fine, but the silkscreen I used for alignment of the interlocking parts did not work out after fabrication. Fortunately, my mistake was to place the footprints to far apart; every terminal screw could be populated.
The issue of Silkscreen over copper. I knew that silkscreen was not allowed on top of copper. I intentionally put some silkscreen over the bare board. I did not know that “no silkscreen over copper” actually meant, “silkscreen only allowed within such tolerance inside of solder mask”.
Care to help others out to share where you had a simple mistake creep in?