Here are my short tips to be more concentrated
Get enough sleep (If you are tired, there is no way of being mentally fit)
Eat breakfast (Many hate it, but it gives you a good start into the day)
Go outside and do so some sport (keeps you physically and mentally healthy)
Be organized (Clean up your workspace when you leave. This motivates you to get started when u get to it in the morning)
Relax and Enjoy :)