Disclaimer: I am primarily an EDH player, so that is where I am trying to apply these concepts
I am wondering what the optimal strategy is for building a self mill graveyard deck with high value instants and sorceries. In my experience, it is incredibly easy to get creatures, lands and artifacts out of graveyards. Enchantments and other misc permanents, less so but there are still quite a lot of "return target permanent" effects.
With instants and sorceries, you have flashback, and a small handful of other things I've come across that recur instants and sorceries. The issue I've run into is losing things like [[fierce guardianship]], [[force of will]] or [[deadly rollick]] to a mill effect. These are response cards that you'd like to cast from your hand without your opponents knowing they're coming. It's also annoying when you are looking for a [[reanimate]] but then you mill it instead.
What's the balance here when building a strong graveyard deck? For now I've gravitated towards discard effects because I can choose exactly what to dump but I would really like to build a graveyard deck that doesn't rely on red or discard in general. I've built [[muldrotha]] without a single instant or sorcery in the 99 and it's kinda fun, but I want to take it apart now.