Pick the most important thing you need to do now and attend to it totally at the exclusion of all else until you finish it.
Sounds simple, however, it is amazing how easy it is to sidetrack. The sidetracking can happen through your phone beeping or through someone interrupting you or another thought cropping up in your mind throwing you off tangent.
The key is to stay the course on what you are doing and not allowing any of the interruptions to distract you. Ideally, you want to put your phone on meeting mode so there is no beeping interrupt you when you are doing important work.
Why is this so important? Interruptions can be the biggest time waster and also a big drain on productivity. One minute of interruption can impact 10-20 minutes of your work. Avoid being sidetracked from important work you are doing and watch your productivity enhance!