“In my experiments, I found I could sometimes achieve approximately 90 dB attenuation by carefully wrapping the generator in foil and double folding the seams on all sides, which is quite good (comparable to commercial pouches).”
Commercial Faraday pouches run $40 to $80. One of them dropped off sharply at 4 GHz and up, right where modern phones talk. Carefully folded kitchen foil matched the paid ones. The vendors also sell Faraday hats.