Ways to increase our Imaan:
1) Love Allah Ta'ala and His Prophet (Sallallahu Alaihi Wasallam) and follow his Sunnah.
2) Have Tawakkul (trust) in Allah Ta'ala.
3) Always have Sabr (patient).
4) Safeguard your tongue, eyes, stomach etc, from Haraam actions.
5) Stay away from Sins.
6) Increase good deeds i.e. offering optional prayers, fasts, charity etc.
7) Seek Knowledge. People who have Taqwa are those who have knowledge.
8) Always remember Allah Ta'ala.
9) Always remember death, as death is the destroyer of all pleasures. Remember what comes after death i.e. grave, when we are judged, whether we will be in paradise or hell.
10) Make Du'a to Allah Ta'ala. Du'a is a weapon of a believer. We need Allah Ta'ala.