No one sets out to write bad code. Yet bad code happens. The world has a lot of it. There are some basic rules you can follow to avoid writing bad code. You don't need to master inheritance, generics, functional programming, lambdas, or closures to write good code. Good code is about more than writing code that works. Good code should also be easy for people to read, easy to modify when changes are needed, and easy to add new features to. Once you have trained your mind to write good code, you will also see how easily you can improve existing code. Examples will be shown in C# and javascript.