Consciousness is hard to define - it arises from perception of the stimuli generated from an environment, the stimuli generated from our senses and the stimuli generated from our thoughts and feelings.
But what is the 'perception' of our own internal states and feelings? That would be a higher-order theory of consciousness. Higher order theories state that one is only conscious of a state when one reflects on that state. So if someone was constantly more reflective, then they could be considered to be more conscious in general.
Consciousness is obviously highly related to how people make decisions then. - If someone is conscious of a certain thing, or how they are conscious of that thing is going to determine how it feels for them and how they are going to make decisions from that conscious awareness.