The Prophet (pbuh) gave us some duas to recite in the most blessed days of Ramadan – the last 10 days. 
Aisha [may Allah be pleased with her] was asked what the Prophet Muhammad ﷺ supplicated during the last ten days of Ramadan.

She replied:

اللَّهُمَّ إِنَّكَ عَفُوٌ تُحِبُّ الْعَفْوَ فَاعْفُ عَنِّي

Allahumma innaka `Afuwwun TuHibbul `Afwa Fa`fu `Annii.

‘O Allah, you are the Forgiver, You love to forgive, so forgive me.’

– Musnad Ahmad, Sunan ibn Majah and at-Tirmidhi.

The Prophet (pbuh) also gave us a tip on how to spot laylat ul Qadr