Are there any standardized steps in validating a circuit design?
This is a very broad question.
There are no &quot;standard&quot; ways to validate a circuit design. It depends on the purpose of the board and the functionality it should have - or in other words, what are the requirements of your circuit? (What kind of power source? how many inputs? how many outputs? types of each input\output, etc.)
Once you get a full list of requirements, you can think on how you will test your circuit to make sure that it functions as required. Example: circuit should work from a 200mAh battery for 3 days on average - you can test for average power consumption and calculate your battery life time (or any other method).
My answer refers to circuit design, but my experience shows that starting with requirements and test plan before starting the actual design is a method that can be used in various fields of development, with very good results.