I don't mind doing it by myself. I have done it by myself several times.
I do, however, prefer to do it with one or two people in my proximity. It's more of a comfort thing for me, like "If something happens and I end up in a bad way one of them will be coherent enough to punch me in the face and shine a light in my eyes" kind of thing but that was for my first couple of times.
Now, more then anything I rather enjoy "Sharing the experience" as it were. Knowing as I delve into the unknown that I am NOT going there alone. And perhaps we might actually see one another there and be like "Sup "M"! Yeah.. Just going to go stick my head into this machine they built. Yeah there is this shiny floating blob guy over there. check him out. Peace!"
That kind of borders on being blasphemous. hehe. I would really do that though.
Also, I like being outside in the hammock or around a fire at night and having nature do it's thing while I do mine. Wind, animals, leaves... all that stuff makes for a very pleasant journey and seems to, for me anyhow, either adds to the experience or does nothing at all negatively to the experience.