Courtesy of maryammasjid.org
Our Prophet Muhammad (saw) said: "Faith wears out in the heart of any one of you just as clothes wear out, so ask Allah to renew the faith in your hearts" (Mustadrak al-Haakim).
Here are some basic steps:
1) Try to increase your prayers if you are not achieving all five. Ask for strengthening of your iman, and forgiveness in your du`a (prayers) along with guidance.
2) Increase the dhikr (remembrance) of Allah subhanahu wa ta`ala (glory be to Him) by reading the Qur'an -- perhaps a few pages a time with translation for those of us who aren't Arabic-speaking. (There's another idea: learn the language of our religion.)
3) Start attending Islamic gatherings, like halaqas (study circles) or weekend programs at the Masjid.
4) Get involved with Islamic charities and organizations: volunteering helps one realize how truly blessed we are and help open the door to attaining more Islamic knowledge.
5) Last but not least, think of death. There are benefits of thinking about death; as noted by Daqaq radi allahu `anhu (may Allah be please with him), "Whoever remembers death frequently will benefit in three ways: he will hasten to repent, he will become content, and he will be active in worship. Whoever forgets death will be punished in three ways: he will delay repentance, he will no longer be content with what is sufficient, and he will be lazy in worship." (Izzah Zaroon)