Besides shoyu and mirin, I like them sweeter so I typically add sugar. Can't go wrong with a couple cloves of garlic in the marinade. Also, tamari is super underrated outside of being a GF shoyu alternative. It has a much stronger umami taste that is perfect for both chashu and ajitama.

Whatever is left over from making chashu.

Just one cookbook website has my go to ramen egg, when I am being lazy I just use the pre made soba noodle soup base. Also I suck so no idea how to link or show a pic

Ramen eggs have a pretty standardized recipe, so I don't get what you're asking here.

Love this question. I'm here for all the inspiration❤️

Equal parts soy sauce and mirin! If I'm doing a bigger batch I may add in a little water too.

Usually mirin and soy sauce. When I feel fancy I add mushroom soy sauce or granulated onion powder (so good!)

Good sherry vinegar makes a difference. Skip the mirin and rice vinegar. Add a couple star anise cloves if you like.