Don’t forget to make your intention to fast before Fajr.

A common mistake people often make in Ramadhan is forgetting to actually make the intention to fast before Fajr.   Narrated by Ibn ‘Umar from Hafsah that the Prophet (ﷺ) said:
“Whoever does not have the intention of fasting before Fajr, there is no fast for him.” (Imam Ahmad)
This is only in regards to obligatory fasts (eg: Fasting in Ramadan). With regard to voluntary (naafil) fasts, it is permissible to make the intention to fast on the day, if you have not had anything to eat or drink or relations with your spouse after Fajr.   This is proven in the hadeeth of ‘Aishah that the Prophet (ﷺ) entered upon her one day at Duha time and said,
“Do you have anything (any food)?” She said, “No.” He said, “Then I am fasting.” (Muslim)
So, make sure before you sleep, or any time up until the adhan of Fajr, that you make the intention in your heart to fast, and let’s ‘Revive Ramadan’.