This is my guide to my favorite ending.
That's the true ending, I recommend talking to the girls more, poking around with the radio in the top left corner of the occult club, retrieving the book without reading it, and returning the theater club room key, and then sitting down at the table. then continue the ritual, cutting hair, drawing chalk lines, but NOT putting down the candles. Don't do anything at all with the candles. Don't touch them. Then explore, I'm sure there's something useful in all those desks...
This is my favorite ending. The only way to mess it up is putting down the candles, and it's truly switched to one of if not my least favorite endings if the candles are lit after going on this path. It'll be relatively quick, in any case.