You could devise excuses to prevent yourself from finishing your book if publishing and selling were never your goals.
There are many ways not to do something, and here are some of them.
1. Ignore your craft
Although creative in nature, a writer must still follow certain writing rules and standards. Now, if you want to doom your novel, overlook the practices and techniques necessary to give your work a proper structure.
2. Write for the trend
Jump on the bandwagon and write whatever is trendy and current. Forget about bringing something new to the table and disregard the fact that publishers are always looking for a fresh voice and new talent.
3. Worry Constantly and Consistently
To worry is to cripple your creative energy. Always tell yourself you are not good enough.
4. Wait for inspiration
Wait and don’t do anything until your creativity finds you, which is unlikely to happen if you’re not doing anything proactive to seek it.
5. Just quit
That’s it. Stop and just quit.