Shaykh Imam Ibn Taiymiah (Rahimullah) has said: If someone would like to know whether their ibadat have been accepted this Ramadan or not, so they should look at their deeds that follow Ramadan. If all those deeds that were done in the holy month of Ramadan are followed into their lives with consistency and steadfastness, then know that most likely Allah (عَزَّوَجَلَّ) has accepted the deeds of Ramadan. Hence, He has given the tawfique (ability/opportunity) to carry those actions further with the same passion.
If you see that the lives remain unaffected after Ramadan and such people have gone back to their previous lifestyle have not been granted hidyah (guidance). Know that these people are the ones for whom the Prophet ﷺ has mentioned:
حَدَّثَنَا عَمْرُو بْنُ رَافِعٍ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ الْمُبَارَكِ عَنْ أُسَامَةَ بْنِ زَيْدٍ عَنْ سَعِيدٍ الْمَقْبُرِيِّ عَنْ أَبِي هُرَيْرَةَ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ رُبَّ صَائِمٍ لَيْسَ لَهُ مِنْ صِيَامِهِ إِلَّا الْجُوعُ وَرُبَّ قَائِمٍ لَيْسَ لَهُ مِنْ قِيَامِهِ إِلَّا السَّهَرُ
It was narrated from Abu Hurairah that the Messenger of Allah (ﷺ) said:
“There are people who fast and get nothing from their fast except hunger, and there are those who pray and get nothing from their prayer but a sleepless night.”
[Ibn Majah: 1690]
Scholars say: The sign of an accepted worship by Allah (عَزَّوَجَلَّ) such as Hajj, Umrah, and fasts have been accepted by Allah (عَزَّوَجَلَّ), the doer continues to get multiple opportunities to do good deeds.
اللہم وفقنا لما تحب و ترضی
O Allah guide us towards that which you love and which pleases you. (Aameen)