I too love the production style of Daniel Lanois....that airy/spacey and harmonically rich/overlapping kind of sound.
About 20 years ago -- shortly after the Lanois-produced Robbie Robertson album, after Emmylou Harris'
Wrecking Ball, long after Peter Gabriel's
So, but I can't remember if Dylan's
Time Out Of Mind was out yet -- I was hired to arrange, produce, and engineer a track for a singer-songwriter who very specifically wanted "that Daniel Lanois sound".
The airy/spacy part was mostly achieved via distant miking, multiple delays & reverbs, and dynamically automating those effect returns during the mix. The harmonically rich/overlapping kind of sound was achieved via
lots and lots of layers of very quiet, very simple parts -- single note drones, sustained pads, and simple two- or three- note motifs -- that continued throughout the entire tune, but again, varied dynamically throughout the mix. So what might initially be perceived as just "ambience" on an
acoustic guitar part would turn out to be this seething, ever-evolving, but extremely background composite of 6 or 7 electric guitars, 4 synthesizers, and 8 FX returns.
That, plus a pair of overdubbed crosspanned hihat tracks, completely
nailed Lanois' late 80's sound.