Drink more water
At least 2 litres per day preferable filtered or bottle water,there are many benefits of drinking more water one that may appeal to all the crypto investors out there that studies have shown that even mild dehydration 1-3% of body weight can impair many aspects of brain function therefore reducing your abilityReduce / remove refined sugars from your diet
Now i won't get too much into the science of different types of sugars but to put it simple refined sugars have no essential nutrients for the body are bad for your teeth and become very addictive. Now this is a hard one as sadly refined sugars are in so many of the foods we buy these days but being aware of this is a start.You could start by not adding sugar into tea/coffee instead use a natural sweetener like stevia also you reduce the amount of candy and cakes you eat.
There is a whole world out there of unrefined sweet snacks you just have open yours,some common unrefined sugars include honey, agave nectar, brown rice syrup, maple sugar, cane juice, date sugar, and my favourite coconut sugar
3.Eat more Fruits and Veg
Its quiet simple one a MINIMUM of 5 portions of fruit and veg a day can help keep the doc away as there are a great natural source of vitamins and Minerals that your body needs for optimal function and prevent sickness. Recommended by the World Health 
you should consume "a minimum of 400g of fruit and vegetables per day.
4.Sleep
The amount needed differs depending on the to person but on average a adult should aim for 7 to 8 hours a day this should not be consider a luxury but essential as it is very important for your health, learning and retaining new information, and hormone balance
- Exercise
This is very important a major key to long healthy life now i'm not saying you have to get down to the gym everyday and lift some weights you can do small things that would still make a difference, some examples would be;
- walk up the stairs instead of using lift or elevator everyday
- join a walking/running club
- take up a sport
-join a yoga class
Exercise will help you sleep better,maintain or achieve a healthy weight ,stay mobile, and reduce risk of depression just to name a few
Thanks for reading hope you can take something positive from this post and remember HEALTH IS WEALTH SO INVEST IN YOURSELF.