Let me flesh out a few very simple proposals: a complaint that a lot of city residents have is that tourists that arrive in a city don't spend a lot of money there because they pack their own lunches/avoid museums, etc.

How about charging a very high tax (in the form of a voucher) for hotel/AirBnB stays, but make that voucher spendable in local restaurants/museums? This would have the bonus that you'd also kill the local black market economy, as tourists would insist on being able to pay for goods using their voucher.