What's your strategy for mitigating PCB design risks?

i usually find it helpful to define to myself the requirements of the design by breaking it to block diagram with each system separated. by doing so, you can understand how every part should connect to other, understand the challenges and identify the risks. after that, you can get the idea of the project needs in time, technology and space, consider your options and think clearly before proceeding.

Also place your components wisely to eliminate any emi effects, place rf components away from power supplies.analog portion should be sperated from digital.

it is a nightmare to finish the PCB design and find out that some of your components became EOL, and no suitable pin compatible replacements are available! you should always check the status of every component, understand if it has long longevity, the price is reasonable and that it has acceptable lead times. for that you should have your distributors in your phonebook, and check on them every time you start a new design.

in your PCB not all the traces have same needs! Highspeed lines should be treated as in the application notes, keep them in groups, make sure that the matching is good, keep the right distance between data and clock, make sure the reference layer is consistent. RF lines should be matched to 50ohm, transferred in outer layers, kept in straight lines with round turns. it will be helpful to keep those thick, so sometimes it is good practice to use deeper reference layer such as l3 for l1. don't forget the coplanar reference too!

never underestimate the power of simulation tools. SI simulation can help you identify timing issues with your design, you can fine tune your data lines to work properly in highest speeds! DC simulation can help you find weak connections, prevent "hot spots" caused by bad power transfer, and prevent power loss. AC simulation will help to predict the stability of your signals in high speeds, and let you know if additional capacitor is needed, or even if a current capacitor is needed in cost reduction process. RF simulations can save you time and money during certification process. it is always better to find the issues in house and fix them before arriving to the certification laboratory.

i find it helpful to have a checklist to check before sending the PCB to fabrication. for example: netlist check, print the schematics, take a marker, check the wirelist generated by your CAD, and manually check each net if it connected to the right place. this will help you to prevent unpleasant surprises during bringup! also you should remember your previous mistakes and check to prevent them, it is normal to do a mistake, but to repeat it? this is a total waste!