What to do after abandoning a patent application

The "intentional" part of that statement generally points to a situation where you're not going to be able to revive it. There are rare instances where an abandoned patent can be revived, and it involves being unintentional or unavoidable. For maintenance fees, you can see if it's still within the payment "window" at least - there's a deadline, then an extended deadline with a higher payment. Actually, it sounds like you did intentionally abandon it by not paying fees. In that case, no, there's nothing more to do.