Let's say you are working on a collection of short stories, essays or posts for a new blog.
Instead of writing exactly the number of pieces that you need, write 20% more than that number. If you're shooting for 20 short stories, write 24. If you're shooting for 10 blog posts, write 12.
Then, strip out the worst 20% of the entire collection.
That material is filler. Just kill it. Take it out.
You can always put more work into that material in the future and use it elsewhere, but for now, take it out. You will vastly improve both the overall quality of your writing and your reputation among your readers.
What's the difference between the greatest music albums of all time and all other music albums? Good music albums have one or two mediocre songs padding the playlist. The greatest albums have all great songs and no filler.