Can I ask a question of anyone that's written the GRE Subject Test - Psychology?

[Shell]

I'd like to know about test writing strategies. I've heard that they deduct points for wrong answers, so I'm not sure at what point I should be guessing, and when I should just leave an answer blank.

Is it better to just go for it if you're 75% sure and leave it if you're only 25% sure? I'd really appreciate some advice here. I'm writing the damn thing tomorrow morning...

THANKS!