You always have to write script with a budget in mind. Although it's always good to write the big story, you really have to think about how things are going to work as far as cast, effects and settings. It's a process. You have to always think budget and then execute and make it happen.
Good horror is the kind that we can all relate to. We all know what it was like to be a child and hear something move in our room. Or how the teddy bear that was so cuddly and nice during the day turned into this horrible, foreboding shadow at night. Those are the kind of things that we all can relate to.
As an independent filmmaker, the biggest challenge is finding the money. Whenever you have interest in a film project you need to find investors who are real. I think most independent filmmakers would echo that sentiment.