To write a good mystery you have to know where it will end before you can decide where it will begin... and I've always known where it will end.
To write, you need to find what you love.
It is much more fun to write about villains then heroes. The villains are the ones that think out the scheme, and the heroes just kind of come along for the ride.
I believe that stories find writers, writers don't find stories. With the 'Pendragon' series, I actually had multiple story ideas and decided that instead of writing them individually, I would create a character whose journey would thread them all together.
I'd love to play the piano, and I'm going to work on it.
The single best piece of advice I give to aspiring writers is to always write about things that they know. I suggest that they write about people and places and events and conflicts they are familiar with. That way their writing will be real and hopefully readers will respond to it. I try to take my own advice.