skywyze: For anyone who might find this topic later, I did some extensive testing using editors and such. Here's what I found:
* Enchanting on Noon or Midnight had no effect on the quality of the enchantments.
* Whether all attributes were set to 1 (Int, Luck, etc) or to 25700 had no effect on the enchantments.
* Setting Water skill to 60 (max allowed) or 63 (max which the game can handle) or at 10 made no difference to the quality of the enchantments.
* Wearing an amulet of water magic made no difference.
* Stages of the moon have no effect either.
For each situation, I enchanted the same 100 rings. I started at 10pm and was done well after midnight. My final test was done during the winter solstice, at midnight, with 25700 in every stat, at level 255, with 63 water magic and an amulet of water magic on. Not one unusual enchantment was gotten. The overall quality of the enchantments was disappointingly average. Maybe even a little worse than without these boost. It just goes to show that the enchantment is totally random and not influenced by anything you do.
I know some NPCs suggest enchanting on the equinox or at noon/midnight. I think a lot of people online are fooled by this. In practice, nothing you can do makes any difference - it's all dumb luck. And I have thousands of data samples to prove it. So just enchant when it suits you and don't try too hard. Nothing you can do has any impact on the odds. It's completely random.
Hope this helps anyone else who might have the same questions in the future!
People like you make GoG fantastic.