As stated above, RL magick is more along the lines of ritualized prayer. It works like this (theories may differ, basic concepts are the same):
Everything in the world possesses energy of some type, scientifically (or is capable of possessing energy). Magickal ritual draws energy from foci (candles, stones,etc) with certain types of energy, chosen for the spell. The caster then takes these drawn energies, combines his/her personal energy (empowered with the exact intent of the spell), and then releases it into one of the cycles of the world, where it will travel, gaining strength, until it reaches its destination. Personal energy is typically returned (at least in part) to its owner (hence the "law of three").
This works on the scientific basis that all things in the world/universe (as we know it) operates in cycles and, therefore, it is logical that energy does as well. When the caster projects energy into a cycle (which most do randomly, as it takes years of practice to "learn" the cycles), and that energy is "programmed" to go to a specific area, once it travels the cycle it will return to that area.
Now, I think the spectacular effects such as levitation are more along the lines of psychic abilities, as spells do not do these things. Spells are more along the lines of manipulating the energy around you in order to have the outcome you desire.
As far as spells go, I've done my fair share (I am Wiccan). As I said, serious practicioners would consider them more like "ritualized prayer". Nothing happens like on "Charmed" or anything of the like.
As far as psychic abilities go, I am a medium. I am in communication with spirits on a daily basis, and usually have to turn off or tone down my abilities in order to prevent myself from constantly seeing them/hearing them. I'm a skeptic by nature (I know, it sounds weird), so I've already checked out the logical sources for this (such as my mental stability), but my abilities are genuine. Most of the spirits I have communicated with can be verified via a few hours searching online, so my communications are genuine. I've helped paranormal groups in the UK remotely (I can use my abilities remotely by looking at a photograph, and they are just as accurate as if I would be there in person). I've also helped a man in the UK find some "lost" history to a castle in Shropshire, and the information I gave was researched further and was enough to have the BBC actually update their page on the castle's history.
Other than that, I'm pretty normal

I hope my answer helped out a bit....