Effective annotation can significantly enhance your reading comprehension and retention. Here are some of the best techniques:

1. Highlighting: Use different colors to categorize information (e.g., yellow for main ideas, green for supporting details).
2. Marginal Notes: Jot down brief summaries, questions, or connections in the margins.
3. Symbols: Develop a personal system of symbols (e.g., * for important points, ? for confusing parts).
4. Sticky Notes: Use removable notes for longer comments or to mark important pages.
5. Mind Mapping: Create visual diagrams to connect ideas and concepts.
6. Digital Tools: Utilize e-reader annotation features or apps like Evernote for digital texts.
7. Summarization: Write brief chapter or section summaries in your own words.
8. Question Formulation: Generate questions about the text as you read.

Remember, the key is to find a method that works best for you and enhances your understanding of the material.