Oct 22.2018, 15:08:15
Any traces under SMD resistors/capacitors should be dead center. Same goes for any traces between pins on SO-8-14-16... packages. (You wouldn't believe how many designs I see where you have a trace hugging one of the 2 pads to the minimum spacing manufacturing rule...)
Keep vias drill hole to either board manufacturer's recommended hole size, or larger by at least 1 full mil, keep extra angular ring around the vias. If you do not need a test point, tent the vias.
Space out traces to 8 mil spacing at least unless you really need the occasional compact point, or are paying for a high spec PCB.
Keep everything away from the edge of the PCB and do not fill planes of place traces, except for an optional single ground trace, under or inside mid layer around mounting screws.
Run multiple parallel vias when feeding high current power traces.