Lets Play - advice?

[Adny]

Don't put on a fake persona, chat with inanimate objects (and when I say chat I mean make both sides of the conversation by yourself), or pretend to react to something or greatly over-exaggerate your reactions. If you want to commentate, make sure you really like doing it instead of just doing it for laughs like so many people do.

Imo, horror is the easiest of gaming genres to commentate on; you can get by on just reacting to the scares and saying very little, rather than having to come up with some witty banter to please your audience.