Lets face it, none of us write perfect code all the time! Especially since there are many ways to write the code to achieve its purpose. The best way to make sure the code is the best it can be is by asking someone to review it! This is even more imporant if you are a beginner software engineer.
Here are imporant things to remember if you are reviewing someones code:
- Does this code check for nulls?
- Does this code include unit tests?
- Does this code meet company coding standards?
- Does this code use generics so it can process different types?
- Does this code validate the data coming into it?
- Is the code readable and easy to understand?
- Is this the best way to write this code, especially when you have performance in mind.
- Will it be easy to modify in the future?
These are just a few things to keep in mind. So if someone does review your code, be accepting and welcoming to it. It will make you a better developer!
My coding standards book will help you in your code reviews!
dotNetTips.com 
I have found many of these things are very much an “it depends” situation, but your list is a reasonable starting point for a beginner. I would certainly add ensuring SOLID and DRY, least access (internal vs. public for example), sealed unless designed for inheritance (which is hard) and a few other things..