How do you concentrate and remain productive for long periods of time?

I make sure to put my phone out of reach and hard to access (I put it in a little tie bag and hang it under my desk). When it’s time to concentrate, I put a timer, so every time I get distracted, I return to the task at hand and train my focus muscles. I also take frequent breaks once every 30 minutes or so to keep my attention span fresh.

Short breaks when I feel my concentration waning – making a cup of tea, tidying my desk anything I can do that's simple for a couple of minutes

I find writing down the distractions and interruptions helps a lot. I’m not going to get upset because my family woke up and started talking to me. I just wrote it down and now I try to get up earlier to get my deep work done before they wake up.

I’m using an app named forest. It prevents me from using my phone.
When I’m working on something, and I get distracted, I write the distraction down, and at the end I go through the list, and if it’s important, I’ll add it to my to do’s