A sketchbook is a gym, not a gallery. Nobody’s supposed to see the sweaty pages.

Practice space and display space are different, and treating them as the same thing ruins the practice. If every page has to be good, you only do what you can already do, which is the opposite of what practice is for. Bad pages are evidence that something was attempted. A book full of nice drawings usually means nothing was risked in it.

Keep one book nobody is allowed to look through, not even as a favor. Fill it with attempts, repeats, and things that go wrong. Post from somewhere else, and let the private pages stay useless to anyone but you.