What not to ask when playing a ouija board?

The appropriate answer to this question likely relies on the beliefs of the one posing the question.

To someone that believes that the Ouija board is a gateway to the afterlife, the appropriate answer will likely be either one of caution or endorsement.

1. Caution: "No questions are safe to ask the Ouija board, because this is a very dangerous instrument that can open up portals to dimensions and entities that should not be meddled with," (as famed prophet Edgar Cayce similarly remarked)
2. Endorsement: "It's cool to ask whatever you want to know about your future and you will be told the answer." (as a less-famed neighbor of mine who proposed to his wife after the Ouija said he should similarly remarked --still happily married and doing surprisingly well).

If you are a believer, weigh the potential outcomes --marital and domestic bliss on the one hand and being tortured by an evil, ethereal being on the other-- and make the choice you feel most comfortable with before you use the board.

To someone that believes that the Ouija board is just a parlor game ("Ouija" is a registered trademark of Hasbro, the manufacturer of Transformers, after all), the appropriate answer will likely be "Ask whatever you want, because it really doesn't matter. It's just a bit of fun nonsense." A cursory bit of research showed no instance of a lawsuit or legal complaint against the company over something that a user was told by the spirit board or any harm that resulted to self or property as a result of using the product, which Parker Brothers (a subsidiary of Hasbro) maintains is a game.

Skeptics would agree with Parker Brothers and have explained the function of the board through scientific means, as noted skeptic James Randi wrote in his Encyclopedia of Claims, Frauds, and Hoaxes of the Occult and Supernatural:

"Actually, the movement is due to the ideomotor effect and this can be shown by the fact that when the operator is properly blindfolded, only gibberish is produced.
The Ouija board was patented in 1892 by a Maryland novelty company."