1. Delegates
2. Events

1. Threading
2. Async and Await

1. Single Responsibility
2. Open Close Principle
3. Liskov Substitution Principle
4. Interface Segregation Principle
5. Dependency Inversion Principle

1. Abstract Factory
2. Factory
3. Singleton

1. Adpater
2. Bridge

1. Observer
2. Iterator
3. Command

Follow all .NET Framework Design Guidelines for both internal and external members. Highlights of these include:

1. Do not use Hungarian notation
2. Do not use a prefix for member variables (__, m_, s_, etc.). If you want to distinguish between local and member variables you should use “this.” in C#.
3. Do use camelCasing for member variables
4. Do use camelCasing for parameters
5. Do use camelCasing for local variables
6. Do use PascalCasing for function, property, event, and class names
7. Do prefix interfaces names with “I”
8. Do not prefix enums, classes, or delegates with any letter