Planning and scheduling work depends upon the priority that you have assigned to the task.
So, that means you will try to do that tasks first which have more priority than with the less one.
What I do to plan and schedule work is, first I make the list of task that I have to do and assign the priorities as accordingly,
Then I first take that task which is having high priority and break down that task in short goals.
Suppose I have to do these three works, make 3 assignment for college, attend a webinar, visiting a friend house.
What I will do first I'll assign the priority i.e. completing the assignment is first, then attending the webinar, and then visiting the friend house.
I will ask my friend that I will visit your house at that time till when I would be able to complete other two tasks.
I'll try to complete the assignment in decided time and then invest my time in attending the webinar.
The key principle is that one should make priority and assign a certain and dedicated amount of time to each task and should have motivation to complete it within set amount of time, this will not only give you motivation but also increases your self confidence.