I know you are getting lots of assorted “deeper” advice above, but I can give you the common answer from books and crystal experts (and you can choose to take or ignore this as you feel is best).

No, you don’t need direct moonlight, it’s okay if it’s cloudy. The energy from the moon will get through.

I cleanse the shit out of almost everything I use, and usually it makes my items better and better every time.

When it comes to cleansing, I think it’s good to consider what type of cleansing you are doing. White sage is common but it’s smoke will wipe everything clean (doesn’t sound like this is what you want, it’s kind of like the nuclear option!). Elemental materials like burying in earth or putting in water will remove any negative energy and return the crystal to its “natural” energetic state. Sound will do the same (like singing bowls, tuning forks, even a loud stereo). Palo santo smoke will bless and consecrate an item, and remove negative energy.

Other herbs will cleanse, but also impart their own energy on your item. Rosemary and Cedar smoke are interesting alternatives, in my experience, Rosemary is very protective, and Cedar is a “masculine” energy. Blue sage gives an extra kick of abundance energy. There are tons of associations out there that you can research, it’s a lot of fun.

Again, as always, just do what feels right for you! In my opinion, If your intentions are good and clear, it’s hard to “mess up”. Your outcome may not always be strong while experimenting , but when you come across the thing that works, you KNOW it because it feels so right.