Guard your time! Each Pomodoro should be uninterrupted, giving you time to focus on just one thing. Find a low-distraction environment, close all web pages except any you’re working on, and put your phone out of sight (and hearing). You can check messages, Instagram, or Facebook during one of your breaks.
If someone interrupts you, either end the Pomodoro and start a new one or postpone the distraction until you’ve finished the Pomodoro. If you can do the latter, explain what you’re doing, schedule a time to follow-up, then return to your task. Not every interruption is easily avoided, but we often allow ourselves to be distracted by insignificant issues. Try telling your friend, “I’m in the middle of a project; can I call you in 10 minutes?” Maintaining your commitment to your Pomodoros will pay dividends as you accomplish more than you realized you could!
As you work, focus on the process (reading, writing, working on problems, etc.) rather than the product (finishing a chapter, completing all the homework, etc.). Focusing on the product can be overwhelming and can lead to avoidance; committing 25 minutes to work on a task is more manageable.