Stop multitasking.
Doing multiple things at once or switching rapidly between tasks is the opposite of focus. So pick one important task and fully engage with it.
Before you move on to the next thing, pause intentionally, take a deep breath, and bask in gratitude for the thing you just did.
If you tend to get bored doing one task, you could set a timer to perform it in short bursts of 15 to 25 minutes.