jesus christ.. not another one of these. Google jenkem there is your fucking household psychedelic. not rly tho.
You could make a nitrous generator (or buy the shit, but if you insist on homemade).. N2O is trippy enough.
You could try to make a batch of acid.. look it up on TIHKAL, it's number twenty-six. If you can understand what reactants you need, how to run the reaction, and the products formed then go for it.
MDMA is much easier to make than LSD... and could probably be done by many idiots placed in the correct situation (proper chems and lab equip). The technique itself is not too difficult.
You could extract or synthesize DMT (if you can't extract the shit, I don't know how you can dress yourself in the morning).
You could go to your local walgreens and pickup some of the wonderful precursors to making the good ol' crystal meth.
But the possibilities are endless and mainly I am making this list to humor myself, so if you find something I've said off color for some fucked up reason, please ignore it and move on.
peace.