Of course, there's some variation. Some people dig for years and never seem to reach anything worthwhile. But if you don't start digging, you'll never know what's in there. So you need to actually write, not just look at the pile and imagine what might be in there. Pitching ideas is just adding to the pile.
Writing is the only way to dig into it.
Many writers use a daily quota, and it's a good way to get yourself started and instill some of the self-discipline a writer needs. You don't wait until you feel inspired. You don't wait until you know what you're going to write. You don't wait until you have every little detail of character and plot worked out. If you wait for anything, you'll probably wait forever.