- Classes
- Methods
- Properties
- Variables
- Constants
- Namespaces
- Repeated code / things that can be split into a different method
- Things that can be split into a new class
- Mixing layers (domain/presentation, domain/persistence, etc)
- SOLID principles are being used
- Ask, don't tell
- Use links to enforce arguments when available
- Remember that we are all proud about our code, don't hurt feelings
- Code reviews are also about praising thinks well done