Answered by Sayyidi Habib Umar bin Hafiz (may Allah protect him and benefit us by him)
What helps us to lower our gaze?
The beginning of lowering the gaze is sincere resolve. If someone maintains that resolve then Allah will allow him to taste the sweetness of faith and thus assist him in continuing to lower his gaze. The stronger the believer’s faith is, the more able they are to lower their gaze.
Furthermore, we should strive to be more present with Allah and we should have a true longing to see Allah’s Messenger. When your gaze falls upon the opposite sex you should envisage the Ka`bah and al-Hujrah al-Sharifah (in which the Prophet is buried) and think about being in the company of the Prophet ﷺ in Paradise. Allah says: Say to the believing men that they must lower their gaze.  Reflect upon this verse and upon Who is issuing the command. Persevere in this and realise that you are in a type of jihad. You will then acquire a hatred for disobedience.
 Al-Nur, 24:30