Here are some PCB design consideration when designing a new PCB.
Incorrect traces. Straight lines, 90degrees bends? Avoid 90degrees bends. Inductors need to have sharp bends. High current traces should be fat.
Incorrectly placed decoupling capacitors. Place very close to MCU powerbpins. 2 types. 10uF and 0.1uF.
No length equalization of hight-speed PCB traces. Important regards to timing for precise time. If a clock signal is going to multiple destinations, the traces must be equaly long.
Improperly designed antenna feedlines. Must have the same impetance as the antenna. Must match. Antenna should be clear of any treaces, planes and ground planes.
Non-optimized component placement. Ref de-coupling capacitors. Be careful with inductors and magnetic fields.
