How do I calculate the coefficient of inbreeding?

There are plenty of articles online that talk about coefficient of inbreeding, but most of them use too much jargon for me to understand or aren't in-depth enough. I want to know how to calculate coefficient of inbreeding for literally any example, which includes multiple generations of inbreeding. My main confusion is about when and when not to add F of A, as it seems a bit erroneous to me.

Basically, what I'm looking for is a detailed explanation of the process such that I have a series of steps to follow which will guarantee me a correct answer regardless of the circumstances. I am perfectly fine with doing a ridiculous amount of calculations.

Thanks!