My first LSD experience, I heard from everyone who got these tabs that they take at least two tabs for good effects. So, since I was experimenting and a beginner, I took just one full tab.
This was a very light experience. A mildly stoned feeling, somewhat stimulating where as you really had to strain yourself to see any type of visuals.
And I can appreciate the people that enjoy these types of doses as well. However, at this point I don't think if I was looking to do some acid, I would do less than two tabs, because the experience any lower then that simply isn't what I would call an LSD experience.
For the first time, my one tab dose was perfect. I was able to somewhat gauge effects, where as they weren't too strong at all and I could hold reasonably well in conversations.
Unless your source has abnormally stronger tabs than most, I think half a tab would be very little of an experience. If you are more comfortable taking half, by all means, do so. Just don't expect much effects, especially since your mind isn't trained to notice what differences are occuring.
But I think you would be safe with one tab each. It isn't too high, and I could even hold a couple of short conversations with sober individuals who didn't know I took anything. Many tabs are different but I haven't found a blotter yet where one tab would've been too strong, even for a beginner.
But each individual is different. In the end, it's what you're comfortable with, because that's the most important aspect of trying any drug.