Focus On One Thing At a Time
This one can be hard. It seems like there are always multiple things pulling us in every direction and it can be tempting just hop from one thing to another and feel like you're getting a lot done. But you're not.
Trying to do a bunch of things at once is a good way to make a little progress on lots of things, but not really get anything done (or done well). The best way to handle the feeling that you need to be working on a bunch of tasks is to prioritize and schedule.
Work on task 1 for the next hour and then commit to switching to task 2. That way you're not neglecting task 2, you have a plan for it, so you don't need to have it hanging over your head as you're working on task 1.
Don't go for the illusion of productivity. Make sure you're actually getting the important things done. And done right.