I thought I should just clarify this before going any further. The word Occult traditionally means hidden, referring to supernatural laws, principles and use of which are not revealed openly. However, in todays world, not much is hidden anymore. Much of what is written about explicitly today had been shrouded in secrecy for long periods of time, the perfect example being Kundalini (for those of you who don't know, more on this later).
The term Occult often conjures up images of Black Magic/Sorcery, but this isn't necessarily implied by the use of the term. Conservative Religions view all supernatural phenomena outside of their own as being therefore signs of Satanic/Demonic activity. Therefore the term Occult often is used with a negative connotation. However, traditionally the term was used to refer to a wide range of practices and beliefs.
The modern religion of Satanism is specifically concerned with expansion of the Ego (this word has different meaning depending on which context it is viewed), meaning seeing oneself as seperate from all others, identifying totally with the physical body and thus encouraging selfishness and hate. This is in complete contrast to New Age and traditional Mystical / Occult traditions which encourage dissolution of the Ego (see the sankrit word Ahamkara for the Eastern definition of Ego, which differs significantly to Freuds use of the term), meaning seeing oneself as interconnected with all life, identifying ultimately with the eternal Soul/Spirit and thus encouraging selflessness and unconditional love. To place Satanism in the same category as modern Spiritualism (for example) by defining them both as Occult is a gross misuse of the term, and is ultimately deceptive.
So, I use the term Occult to describe things like knowledge of the Astral realms, and laws that govern them. For example the Hermetic text The Kybalion is a short series of Occult Principles which relate to both natural science and metaphysics. Used in the context provided within the text, these principles can be used for positive spiritual growth. However, if one goes against the strong warning of all serious spiritual philosophies and chooses to use knowledge of such principles for selfish or destructive purposes then you are in the realm of genuine Black Magic.
So, the term Occult refers to the the Science (many people will object to my use of this term here, I understand) specifically and not the use of it. Just as modern technology can be used for either productive or destructive purposes, so can Occult knowledge. This is the traditional meaning of the term.