Focus is like a muscle.
For one day only, try to do just one thing at a time.
When you're on a phone call, only be on that phone call. Don't let yourself use a computer, or let yourself scroll around on your phone while talking to other person. Just be on that call. Sit and give it your full attention.
When you're going out for a walk, try to walk without any music or headphones in. Experience the walk as best you can. Pay attention to your steps, and to the sounds and sights and smells around you, if any.
When you're working in a program on your computer, try to use it full screen. Try to start and finish it before moving onto anything else.
Try to only keep one tab open in your browser at a time. Read an article start to finish before moving to the next one.
If you're watching a television show or movie, pay attention to only that screen. Try not to add in a second screen like your iPad or iPhone. Just watch the show.
If you're talking to someone in person, just talk to that person. Give them your full attention. Don't hold your phone in your hand, or check your watch, or do anything to draw attention away from them. Listen to them as if they hold all the secrets of the universe and you're learning from them.
In other words, really try your best to do just one thing at a time. Give anything you do your full attention. It probably won't be easy -- it's not easy for me to do, and I try to do this every day.
But it's amazing what a difference it makes. To work on that focus.
Focus is like a muscle. It's really hard to use. It's hard to stay focused, especially in a world that has so many rewarding distractions like notifications, likes, hearts, comments, breaking news, multitasking apps, etc.
If you work on your focus though, you'll begin to find deeper meaning in what you're doing. You'll notice things you would have missed entirely. You'll feel calmer, your brain won't have to work as hard to constantly move between different things and try to keep up. You'll find that you retain more.
As you grow your focus skill, you'll find it's easier to get things done. It's easier to start something and finish it. It's easier to make progress.
Try your best to be present in each moment, and stay focused in those moments, and see how it feels.