James K. A. Smith, associate professor of philosophy, Calvin College, details three key elements of phenomenology in his article, "Determined Hope: A Phenomenology of Christian Expectation." I'm going to quote the entire few paragraphs here, risking redundancy, because Smith's explanation is so straightforward.
"First, as Edmund Husserl observes (in contrast to Descartes), consciousness is intentional; that is, consciousness is never without an object or a world; rather, I always have before me--whether I am perceiving, judging, feeling, or remembering--an "object" of consciousness. I cannot think without thinking of something. Thus, the first fundamental insight of phenomenology, known as the doctrine of intentionality, observes that consciousness is always consciousness of.
Second, the object intended is constituted by the ego. This simply means that the ego "makes sense" or, literally, "gives meaning" (Sinngebung [Sinn, meaning; -gebung, given]) to experience by "putting together" or constituting the data of experience into an identifiable "object." The wave of data coming at my senses right now is "put together" and "make sense of" by consciousness so that rather than waves of color and light, I perceive before me a screen, books, a watch, and so on. Anything that would be completely undetermined could not be constituted into an object, and thus could not be "intended" in any way. it would have no "significance" (recalling the connection between something having meaning and being significant) and could not, in the technical sense, be "experience."
Finally, this process of constitution can happen only within horizons of constitution, which provide the context within which I "make sense" of what is before me. In other words, constitution happens within horizons of meaning which enable me to see the object before me as a lamp or as a cup. Thus these "horizons of expectation," we might say, while functioning as conditions, are also precisely what enable me to make sense of my experience."
 Consciousness is described as "intentional" because it always "aims" at objects; the Latin term for this kind of aiming (found in Aquinas' epistemology, for instance) is intentio. In Husserl's terminology, to intend an object is also to "mean" an object, to intend it as something; this relates to the principles of constitution and horizonality.
This is a largely passive process according to Husserl, and is governed by processes of habituation and the historical formation of the ego (at least as it is described in later works such as Husserl's Cartesian Meditations).
 This is analogous to the role of as-structures in Heidegger's Sein und Zeit (Berlin: Akademie Verlag, 2001). It is precisely when these horizons are "out of joint"--as in cross-cultural situations--that I constitute objects differently. I might, for instance, like Ariel the Little Mermaid, find myself in a foreign environment where I have difficulty constituting the objects before me because I lack horizons, or I constitute them differently, as when Ariel spots the fork and constitutes it as an object for combing her hair.
James K. A. Smith; Edmund Husserl; phenomenology; consciousness; Martin Heidegger.