Focus (verb) - to give attention, effort, etc, to one particular subject, situation, or person rather than another [Oxford Learners Dictionary]
If you check the definition carefully, you’ll see that focus begins with a choice. You have to choose what to give your attention to. But many of us don’t have a system for making choices, how to decide. I wrote about my system for making decisions here. You may find it useful.
But I want to say something special about focus. Once you’ve decided what you will concentrate your effort on, how do you maintain that? Again, a system. Here’s mine (it’s still hard for me but this is what I come back to)
Decide on how long to focus on that thing
Allow for unforeseen distractions
Consciously bring your mind back to that thing every time it wanders - very important
Find a space that will make focusing easier
Let others know what you’re trying to achieve and ask them not to interrupt for the given time period
Refine - don’t be too hard on yourself; adjust where necessary
How do you focus?