It is desires and impatience that weaken the will, especially the sense of urgency to gratify an impulse.
By not acting impulsively, by postponing or delaying gratification, by cultivating patience, by being deliberate and conscious, weighing it with reflection before choosing to act, especially rather than rushing to act we strengthen the will.
In any activity, physical, intellectual, emotional try to push yourself a little more each time.
Take life and its difficulties as challenges to be endured and conquered rather than to be complained and grumbled about.
The effect will be a growing inner mastery and freedom, peace and joy.
Affectionately,
Alok Da