When sitting quietly in the evenings we sometimes find ourselves worrying about our workday and focusing on the negative aspects. We often have a feeling of a heavy chest or a knot in the stomach. This is because psychology (our brain) is inseparably linked to our physiology (our body).
To overcome our brain wandering down that terrible spiral of worry about the day leading to guilt leading to regret leading to overwhelming defeat - you get the picture - a way that I find works well is train the brain by diversion.
To do this we link a physical action with a mental action, i.e. we do something while thinking something. An example; you recognise that you worry about work when you get home. So, when you do get home combine a physical action with a mantra such as hanging an article of clothing on a hook and saying to yourself, "I am home" or "work is over" or "I am safe".
Do this everyday for 21 days to start the change, 66 days to embed it. After this period all you have to do is the same physical action and your brain will automatically forget about work, you won't need to repeat your mantra.