For almost all the electronic engineers (EEs), it's their daily activity to design printed circuit board. However, no matter they are full of experience or a green hand in this field, it's not an easy job to design circuit boards with high quality. A lot of elements have to be taken into consideration. First of all, requirements in terms of functions must be fully met, of course, which in itself contains many details such as the routing design, schematic design, component placement and more. Besides, other aspects must be considered as well, including the schedule and cost. This passage will provide some tips of how to design high-quality PCBs.