First smoked Salvia dried leaves whilst travelling in New Zealand a couple of years ago. Smoked them in a little pipe with the lighter flame continuously on the leaves. I smoked the lot and what happened next couldn't be described properly but here goes...
In a split second I "moved" from day2day reality (YIH room) to "outer space". All I saw was the vast emptiness of space, black, with "me" floating in there somewhere. Next I saw what I can only describe as the Dumbbell Nebula (yes I'm a star gazer). An enormous consciousness emanated from this "planetary nebula", a consciousness higher than Buddha's... All "I" could scream was "how can I ever be BIG again?!?!?", meaning how can I ever have an opinion about myself, have an ego. I felt SO small in comparison.
This flash trip lasted only seconds but it was a great lesson in humility.

Later trips where back home, with the 5 or 10x extract from a headshop in my area. I smoked a small pipe load with a homemade pipe (from a local tree). I had read "Divining Ecstasy - The Magical & Mystical Essence of Salvia Divinorum" by Dr. Sean Shayan, so I asked my bf to sit with me. As soon as I took the second take I fell over backward on the bed and watched him take the pipe and put it somewhere safe. I felt great! The room was still the same but I was definitely in another sphere Suddenly my view split in 2: there were now 2 rooms, 2 realities. Then my view/reality split into 10, then 100 then a thousand! There were now 1000 views on reality and my bedroom! The amazing thing was that not all of these realities where identical! There were minute differences. The thought arose that 'this is how god sees us', sort of like seeing all the infinite possibilities.
I figured I had this pretty much under control and asked my bf to leave the room as him anxiety about these things started to interfere with the experience : confused: Then... things changed again. I was no longer in the room. The overall feeling was "1980" how do you explain "feeling 1980"??? + there were voices of clowns and circus people laughing and talking in France (as they speak in France; I'm France). This re-occurred in later trips and I figure this is an association with the suppliers of the product being France. Funny though
Then followed a hilarious scene from the Belgian TV series "Lava" (with Kamagurka and Herr Seele) going something like "in het heelal is 't alle dagen carnaval" (literaly: in the cosmos, every day is carnival). It was SO true I couldn't stop laughing and nodding my head in agreement. I wanted to share this truth with my bf so I shouted and shouted but he didn't come. Figuring he was mad at me or something the trip soon ended. As it turned out: no words were uttered. I had been yelling but in this day2day reality no words were heard.

Subsequent trips were less and less intense. For me, anticipation, set and setting are key factors in a successful trip.
I can recommend the cited book.
Also: I only pursue natural highs and get there in combination with meditation. This method allows for a peaceful mind before commencing the trip, gives you more control, helps you remember more. It should be understood that simply and purely meditating can take you "higher" than any substance use.

Take care and have fun exploring!