Not suggesting you follow my regiment, however, I usually take at least 2 hits of acid at a time. A single dose (at least what is pawned off as a single dose), doesn't get me where I want to go typically.
If the LSD is pure/clean, multiple doses have no toxic buildup effects, which may occur if you got the acid from someone you don't know or trust, which could have adulterants which accumulate and could cause unwanted effects when doubling doses or more.............(ie. stomach cramping, etc.)
With mushies, for me, I believe there is also a "breakthru" dose that separates the weekend funsters from the true seekers......
Again, not suggesting anyone do "heroic" doses without realizing what they may be getting themselves into, or what may be in store for them..........
However, I think at high doses, shrooms are more DMT like than LSD............