In the days of Howard Carter essentially nothing .. and one can argue that there was no archeology then, as we understand it today, just glorified upmarket treasure hunting that destroyed invaluable layers in order to wrench gold trinkets from their settings.

Today there is procedure, as dull as that sounds, that makes it very difficult to plant evidence and get away with it (as evidenced by your linked story).

The majority of significant digs are proposed and planned some months, years even, in advance. The sites are photographed, scanned with geophysical instruments, and the stakeholders are many - land councils, archeological councils, the actual teams with feet on the ground, etc.

As trenches are dug photographs are taken, when 'something' pokes up a bit it's immediately photographed up close and measurements are taken before being carefully removed.

To stage a find would generally take more than one person and they'd have to operate in a sea of oversight.

I wouldn't claim that this is impossible, I would say that's its very hard to pull off and even harder to keep a secret for many years without someone being suspicious.

Significant artifacts get a great deal of scrutiny .. so one would have to be created that had no trace of modern tools, materials, post atomic age isotopes, etc.