If we stick to the more original form of Wicca (i.e Gardnerian Wicca) then we can definitely outline what the overall philosophy and beliefs are. Other branches or traditions are generally the same, though the religion has evolved and changed over the decades.
Now, philosophy isn't quite exactly the same thing as a list of religious practices. The fact that Wiccans generally celebrate 8 sacred Sabbats every year isn't a philosophy, but the idea that they revere nature and the cycle of life would be.
So here are the main points of Wiccan philosophy:
The Divine is Dual
Though many adaptations of Wicca have taken on the larger pantheons of ancient civilizations (like Greece or Egypt), the basic philosophy in Wicca is that Divinity is made up of a God and a Goddess. The male/female split in nature is reflected in the Divine as well, and is one of the central tenets of Wicca.
The Reality of Magick
Not all Wiccans do spellwork to the same degree, but the belief that magick does exist and is part of the religious framework is a central part of Wiccan philosophy.
Holding Nature Sacred
I mentioned this one a little earlier. Wiccan's believe that nature is an extension of the God and Goddess, and the natural cycles of the seasons are celebrated. These cycles also include the larger one of life and death.
All Paths are Valid
Wiccan's do not believe that their path is the only spiritual path, like many other religions tend to do. All ways that lead to the Divine are acceptable and everyone has the right to find their own way (providing of course that they're not hampering others in the process).
Faith is Personal
Even when working in a coven, you are connecting to the God or Goddess on a personal level. You are responsible for maintaining, building and understanding that relationship on your own.
So these are the general tenets of
Wiccan philosophy. As I said, this isn't about practices, but more about general beliefs. Each tradition or coven may have their own variations on these themes.