First, try to identify what actually pulls your attention away from your work. Divide your distractions into several categories and try to figure them out.
Create a noise-free environment for your workspace. Use noise-cancelling headphones or listen to music without lyrics to maintain your focus. You can also do 10 minutes of meditation.
To make your task less daunting and easy to tackle, divide your large task into manageable chunks. Focus on your urgent tasks first and allot time for them.
To have a focused working hour, utilise your time in some mental math puzzle-solving activities, or you can also choose to do meditation. Avoid multitasking, as it will not be beneficial in the long term.
If you are not able to handle your internal distractions, like a habit of procrastination, find out their root cause and work on it first. Be kind to yourself when you get distracted.
Regularly assess your focus and productivity. Identify what's working and what's not. Based on your evaluation, make adjustments to your strategies.