Tradecraft hasn't changed much. It has been fairly well tested. Operational security and information security have not changed much... They have become more difficult with cell-phones and small internet connected devices.

I think another big difference and a subject that probably would be included in a redo is understanding how all of the modern data generating systems can reveal covert activity through the analysis of metadata and how to "hide in the noise" of this.

The geospatial correlation of burner phone to actual identity if one does not practice good sanitation as far as locational security when accessing wireless networks as an example.