As mentioned above turn stuff off that will interfere with your concentration when working. I put phone on silent and put in another room, shut down email programs, turn off TV or radio etc.
Spend some time dedicated 100% to what you're doing and that time will be 10x more productive than if you have distractions. You'll be amazed what you can achieve without distractions and most importantly when you're in the right frame of mind. What I mean by 'right frame of mind' is that some days you're just not on the ball, heads up in the clouds for some reason.
If my day starts like that and I can't concentrate for one reason or another I go and do something else. This might be fishing for a few hours, doing the garden, washing the car, walking the dog. Anything to clear my mind, then when I'm ready I work I do. Problem is that might be in the middle of the night lol.