The most important thing that a Muslim can attend to and take care of his daily life is acting according to the Sunnah if the Messenger (PBUH) - until the person organises his life in accordance to the Sunnah of the Messenger (PBUH) from the morning to the evening.
Dhun-Nun Al-Masri said:
From the signs of one's love for Allah, is following His beloved Prophet's (PBUH) actions, manners, commands and recommendations.
Allah (SWT) says:
"Say; if you really love Allah then follow me and Allah will love you and forgive your sins. And Allah is Oft-Forgiving, Most Merciful.' "