Concentration and love are one - like two sides of a coin. Love should be there if you want concentration.
Love is the center-point of life. We should perform all our actions while remaining focused on this center-point.
We need to focus on our destination. Let the thoughts arising in your mind pass by, like watching scenery through the window of a car. The thoughts cannot affect you if you don't allow them to capture your attention.
Spend each moment intensely focused on the spiritual goal of life. Take a pledge to put effort in this direction.
An artist paints with focus; the painting becomes complete only through ekagrata (one-pointedness). Similarly, whatever is our goal, we need focus on that to make it complete.
Chant your mantra while engaged in work. This way, the mind will be continuously focused on Him.