Great question Rachelle :) I believe you'd get a couple hundred different answers if you asked a couple hundred people. The reason for that would be how different each person's journey is and what lessons they're here to learn, what dreams they want to actualize, and even what justifications they may be telling themselves for not taking action to be all they can be. Life can sometimes seem to get in the way of fulfilling our purpose, focusing on why we came here etc.
Whatever we focus on grows - this inevitably means that what we're taught to believe may not be authentically "us". Its been said that people spend more time deciding on what car to buy than what career to choose.
Synergy within - making sure our conscious and subconscious are in unity definitely helps us actualize our dreams. Unfortunately, without this awareness, our fears can create as fully as what we think we want. Whatever we hang onto emotionally can do the same because our subconscious dictates our actions. Knowing everything happens for a reason can definitely keep us alert to the profound reason for any circumstances in every moment. How many people do you know who are totally in the moment and accepting?
In a nutshell, self actualization to me means to be completely aware of who we are, what we're thinking, feeling, and believing; staying true to ourselves, and nurturing our spritual growth. When we do, we will create/actualize whatever we need.