So I've heard, as I'm sure most everyone has, that the phases of the moon affect the workings and spells cast in accordance. The reason for the moon phases is simply the angle of the sunlight on the moon face, so my thinking is that the "moon phase" correspondence was developed by people before they actually knew what was going on.
Basically, the amplification the moon phases grant is caused only by the sustained belief of this, and really the moon phase has no effect by itself on casting. That's just my thought, what do you think?
The moon affects a lot of things. People are a little "crazier" on a full moon. There are more admittances into the hospital on a full moon, for example, than on other moon phases. That being said, many people believe, that since it affects the natural world a lot, there is no reason it would not affect spell work.
My personal opinion is that it can affect spell working, but I don't often use it. If a spell I am wanting to cast just so happens to fall on a moon phase that coinsides with my working, then I use that. If it doesn't, then I don't worry about it.
Honstly there are theories out there of it, but I don't know if there is actual proof. The moon and the cosmos are often believed to be tied in with us and how we act, however it does not control us. This would be within the field of astronomy a practice which has been around for thousands of years.
The tides of the oceans are effected, so why not would it also affect energy? Did you know more babies are born on full moons? And it is true that more visits to the emergency room happen on full moons. I know this to be true because my dad would comment on how busy he was to be on full moons. He was x-ray tech. lol It's not the light, or reflection of light, that counts. It's the alignment of the moon and earth that happens during these phases. The more in alignment, the more the "pull" on the gravities and energies. I'm one who feels it, to the point of affecting my sleep. So, yes, I know it has an effect. But not all spells call for the moon to be in certain phase. Adding magick to your cooking is an every day thing. Protection is done when it is needed. Healing with herbs, light, energy are done when needed. But indeed, the moon does have effects on us, and our magick..