If you continue to mix things up every now and then with your side project, not only will you and your audience stay interested in it, but you’ll never peak. You always want to be improving and growing as a creator.
As your side project grows and improves, so will your goals. You’ll get better at setting tham, at knowing whats realistic, and at reaching them too!
Systematise the boring, repetitive parts of your creation process. Find ways to save time where you can so that you never feel like you’re in a boring routine, or that you’re wasting your time.
If your side project is a solo one, you need to stay accountable to yourself. Give yourself due dates. Give yourself a schedule. Whatever it takes to stay on track.