Add in some sort of continuity.
This will depend on your level of expertise.
Simple add-on is hosting.
I provide client hosting from $100/month - $1000/month with all ad-hoc hourly work at $100/hour, so some clients may pay $10K+/month.
You're welcome to give me a call + we can run do an inventory expertise for you + figure out a monetization approach to reach your goal.