First and foremost, dhikr (remembrance), the remembrance of Allah.

That is, to understand the meaning of the Word of Unity (La ilaha illaAllah) and to view life with this understanding.

Salat is ascension, from your assumed self who thinks it has a separate existence, to your Rabb, the One who administers all things and is fully present in every iota of His existence.

Fasting is also very important because it fortifies the understanding that you are not this body and enables you to have some degree of control and administration over the body.