Do regular exercise to increase the concentration power, as doing exercise regularly has many benefits.
Make a proper sleep schedule and try to take an 8 hour of sleep which will help you in doing your work with more focus and concentration.
Spend some time in nature also, do not sit on your screen for the whole day.
Try doing meditation for 10-15 mins, this will improve the concentration power more.
Avoid doing multiple things at a single time, by doing this you won't be able to do the single work properly.
Listen to your favorite music in your free time or when you are in the break, it will help in relaxing the mind.
Do take a break between work otherwise, it will lead to more pressure and you won't be able to do the work with your full focus.