1- Recite Dua Ahd every morning and Dua Nudbah every Friday
2- Pray two rak’as everyday and gift them to Imam Mahdi (a)
3- Pay Sadaqa on his behalf daily
4- Read about him as much as you can. His biography, the minor occultation, the major occultation, signs of reappearance, how the world will look like when he reappears, and so on.
5- Educate those around you on the Imam. Conduct weekly reflection sessions on him and how to serve him.
6- Write about the Imam. Introduce to people on social media and other platforms.
7- Do charity work in his name.
Some good books to read:
May Allah bless you