Phenibut will always be the GABA drug that I add to LSD and any other psychedelic experience. I don't like alcohol. Benzos dull the trip for me and take away any sort of spiritual benefit (even at small benzo doses). Carisoprodol with Allylescaline I wasnt a huge fan of, would have preferred one or the other; though I know that
@Esperighanto speaks highly of Soma+LSD. Amanita during the comedown of LSD is nice. GHB I have never used with a psychedelic, though I feel like it'd be too sedating. Thats why I like phenibut; anti-anxiety, non-sedating, and it doesnt take away from the trip at all.
I am a fan of L-Theanine. I have used it often for anxiety attacks and also to help get to sleep after a dissociative session. Don't think I've tried it with any psychedelic.
Haven't tried zopiclone or zolpidem with a psychedelic, either. Zopiclone might not be too bad. Zolpidem might be dangerous with how randomly people respond to it on its own