You can also build your will-power by restraint in your conduct with others. Speak less (use the 60/40 Rule = listen 60% of the time and speak a mere 40%, if that). This will not only make you more popular but you will learn much wisdom as everyone we meet, every day has something to teach us. Also restrain the urge to gossip or to condemn someone who you feel has made a mistake. Stop complaining and develop a cheerful, vital and strong personality. You will greatly influence others.