This may be a place where writing for magazines for instance is a good thing.

Standup comics try out new material on tour, and then save up the bits that work for big gigs and specials. Creative writing isn't that different from joke writing. Write yourself a bunch of short stories, try things out, see what sticks, novelize the good ones. Spinning Silver by Naomi Novik was a short story. There are some famous books out there that were originally done as serials.

Do more, but find ways to shed the unsuccessful attempts, or otherwise give yourself permission to fail. If you're not failing occasionally you aren't reaching far enough.