Designs have the natural beauty of logic. This means for every design there is always a "perfect" way to implement it. Believe it - it's true.
Every bug has a reason; In other words a basis in logic. Whether the bug is due to bad hardware / peripherals, or if it's because of a bad compiler there is always a reason. Every step of the programming process from the designing to the running can be explained. Bugs are usually the product of an error in the design or implementation, and rarely a problem with the tools or hardware - although nothing should be discounted when attempting to solve a bug.
I'm an amazing debugger. I use very few tools, and I do most of my debugging manually - but I almost always get to the bottom of things. The only reason why I can do this is because of my strict belief in logic, and perhaps the massive amount of experience that I have in debugging.
Be very suspicious of other people's code, and be very suspicious of APIs. This has served me extremely well over the years. This advice must be taken with care. For example it is obvious that most Win32 API calls are gonna work the way they should since they are used in countless systems since whenever Win32 API came out - a while ago. But if you are using the API from a very customized chip maker and the chip / API is new - then be suspicious. Any time you want to suspect an API you must be able to explain at least in theory how that API is only causing you a problem although it's working for other companies / users of the same API.
Other people's code is always a source of friction. Most people take pride in their code and don't like when you look at it suspicously. I'll say this "If the system isn't working then the first step is to look at the code as if it's 100% the problem." Don't listen when people say "The bug isn't in my code." Everyone believes that and someone's wrong. Take this advice with care. We all know that some people are more prone to bugs then others. And that should affect which code you are more suspicious of to begin with.