Most hallucinations that i've ehm... 'experienced'.. aren't more like huge things appearing from nowhere or things in places they shouldn't be, but just a total mindfuck with reality. Rooms that look infinitely tall , field of view being fucked around with , colours not seeming right , everything looking a bit like 3d in the cinema - everything flat but things "pop out" from one another , like layers - , just really fucking weird. It's not necessarily new things, just fucking around with what you already have.
oh and paranoia isn't good , let me tell you that.
whatever you do in the mod - DONT :
add rainbows. rainbows are stereotypes and they do not appear when you are hallucinating. Everything isn't flashing colours , either. ( unless you are on ecstasy)
stretch and skew and rotate the view ridiculously. In charlie & the chocolate factory , when willy fantasies about the chocolate , the view is warped like actual fuck , strecthed and skewed. I've experienced the warping and it is nowhere near as obvious. You know something is wrong, but it's not "OOOHHH SHIT MAN". Combine this with changing the FOV to something ridiculous and you have a good effect going on ( something like )
i should probably stop talking now