How to improve Psat to Sat help?

hey i just did pretty poorly on my psats... i got a 152 which is far from what i expected. and actually went down 8 points from last year. I don't know what to do because i want to should for the 2000 this spring on the SATs. I am a straight A student but i just feel liek all the work i had done didn't pay off and discouraged to as it will or not.. How do i improve my score. I had taken an 8 week preparation cours during the summer as well...