It's really not the easiest. You have to prevent gifting things at a lower tax rate while alive. That means it comes bundled with income tax or gift tax implications.

Fairest? I mean, land value tax is fair. So are Pigouvian taxes. In fact they're arguable more than fair. Not having these taxes is arguably unfair. Who deserves ownership of natural resources or to inflict negative externalities on others?

Taking things someone earned through labour and not letting them give it to who they want isn't very fair.