Harry/Cassandra
Never use your powers unless something comes to you.
Sybil Trelawney was the one who prophecized about me and Voldemort. Our entire lives, hers included, were shaped by that one prophecy and guess what? Whatever had to happen still happened and the last part of the prophecy didn't actually work the way people assumed it worked.
On the other hand, if something does come to you naturally about where everything is stashed write it down. We'll use together with everything else we can gather.