Rubber Duck Debugging: explain your code line by line to an inanimate object.

Use a pointer or your finger to guide your eyes. This can increase reading speed by 25%.

Follow the 20-20-20 rule: every 20 minutes, look at something 20 feet away for 20 seconds.

Take brief notes after each chapter. Summarizing helps cement knowledge.

Write documentation as if the next person reading it is a violent psychopath who knows where you live.

Use the Feynman Technique: teach what you learn to someone else to identify knowledge gaps.