Listen to this sound, it really helped me to stay focus while doing something https://youtu.be/WPni755-Krg

Don’t let your head become preoccupied with things we shouldn’t be doing by getting rid of anything that can distract you. Well, numerous exercises to help you focus better are accessible on the internet.

i will make a to do list and the time needed to complete something that needs to be done...

It depends, but for me I think about the present—what I'm doing right now rather than waiting for it to finish.