Send salawat when he is mentioned
الْبَخِيلُ الَّذِي مَنْ ذُكِرْتُ عِنْدَهُ فَلَمْ يُصَلِّ عَلَيَّ
Al-bakhilu alladhi man dhukirtu 'indahu fa-lam yusalli 'alayya.
"The miser is the one who, when I am mentioned in his presence, does not send prayers upon me."
Narrated by 'Ali ibn Abi Talib. Jami' at-Tirmidhi 3546 (sahih)
A short reflection
One of the easiest acts in the deen — seven syllables each time his name is said. Miss it and the Prophet ﷺ called you stingy.