The key to all good deeds is sincerity.
There are some other useful definitions of ikhlas:
– It is the freedom of the desire for nearness to Allah from every blemish or impurity;
– It is singling out Allah with one’s intention in all acts of worship;
– It is forgetting the sight of the creation by continual observance of the Creator; and
– It is to hide your good deeds just like you would hide your evil deeds.