I learned about salvia a couple months ago. I'm the kind of person to go THROUGHLY into research before I try and do something myself.
So far I've experienced many threshold doses, and 2 light doses. The threshold experience for me is knowing the salvia is obviously doing something to me. I usually like to lay down and experience it. Light ringing in my ears, reality is slightly dreamy for a couple minutes. sometimes if feels a bunch of little entities are trying to pull away my reality and they are excited to take me on a jounrey, but I haven't taken enough to actually go on that jounrey yet lol
the light doses I've had, the first I was sitting in my chair and I started to become a rusty gear in some big machine. I was still half into my normal reality during this though. and the second, I was sitting on my couch alone at home with my dog. I started laughing a ton, my dog started stairing at me like I was a completely different person in his home. I started talking to him during this, but I don't remember what I said. It was a feeling of being an observer of some other entity inhabiting my body, getting a taste of what it is like to inhabit the vessel
I've been wanting to go deeper, kinda scared, but I know I eventually will. I've heard most people get turned off of salvia very early because they go too deep too fast, but ramping up over time can have a much more respectful, sincere approach to the plant, and whatever entities it leads you too.