I just write. I write bad ideas, good ideas, silly ideas, you name it. I have a lot of stories that are just plain bad, but no one will ever see those stories. Also, being the illustrator as well, I do sometimes get illustrator block. I just don't know how to illustrate this page. I handle this by putting the book away for a while and work on another project. Always keep working, whether it is writing or illustrating. It will come to you.