Humans are habit-loving creatures. Our brains desire the comfort of returning to the familiar over and over again - it becomes programmed. There is generally negative sentiment when we hear the word 'habit', but thankfully we can develop good ones that are consistent with the way we want to live our lives.
Reading is absolutely a must for everybody who can - "he who thinks he knows everything knows nothing at all"; you should always be striving to further your knowledge. Reading provides you with valuable insight into various topics, and reading opinions that conflict your own is another important discipline to keep. Ideas are just that - you should never be married to an idea or concept if you wish to approach things with an open mind. It's also a great excuse to get off your phone or laptop and unwind.
I've been a fan of mobility work for the last 3-4 years - the effects on the body and mind after even a light 5 minute stretch are immeasurable. Stretching is a measure of injury prevention, but also a great supplement to training in general. Getting deeper into stretches requires you to be conscious of your breath, and deep breathing helps lower blood pressure and improves oxygen absorption in the body.
3. To-do Lists
The mighty to-do list keeps you accountable to the tasks that need doing. It also gives me a great sense of relief when I tick off a task that had been looming in the background. Don't make your list too long or it will become overwhelming - try sticking to the 5-8 most important tasks, and order these by urgency. Do not start a less meaningful task until your most difficult task of the day is out of the way.
Our day to day lives are consumed by an overwhelming amount of stimulus. As a species, our attention spans have never been shorter. We're always on our phones, or watching TV or working on a laptop. When was the last time you sat and actually did nothing? I try to take out 5-10 minutes per day to sit and observe my thoughts without reacting to them. I've found it really helps with mental acuity and energy levels. You can also use guided meditation apps like Calm or Headspace if you don't know where to start.