Coming on Strong was described as a "successful but safe entrée to the British electro-soul outfit" and although "graceful, delicate melodies of the debut" had been abandoned, they were replaced for "songs with more wallop".

[4][6] The production of The Warning was handled by vocalists Alexis Taylor and Joe Goddard, who produced and recorded the album in the band's Putney home.

The album was recorded mostly using live instruments, including tambourines and bongos, but multiple vintage synths were also used in the creation of The Warning such as a Roland SH-101, a Teisco 60F and a Casiotone MT-70.

Goddard stated a preference for using a mix of analog and computer sounds rather than a concentration of Virtual Studio Technology (VST) instruments.

Felix Martin wasn't able to participate due to severe illness, so fellow band members "had to figure out how to do his parts whilst [doing their] own" and enlisted the help of LCD Soundsystem drummer, Pat Mahoney.

[13] AllMusic said that "Over and Over" had "DFA signature production" and described the chorus as sounding "hauntingly similar to something Paul McCartney would write had he been paying attention to the music of the youth in his own backyard.

"[6] The production of the title track, "The Warning", was likened to outtakes by The Postal Service and it was said that it "wouldn't [sound] out of place on I Am Robot and Proud's last few records".

[5] Prefix magazine's review discussed the idea of antithesis in the song, "The Warning", which had "soft glockenspiel notes" in contrast with "violent" lyrics.

[5] Pitchfork also said that "momentum and retraction" of "Careful", which "opens softly and quickly erupts into choppy sample darts, then cools back down again" was "a good metaphor for the [whole] record".

[6][7] AllMusic said that "the core of what made The Warning [...] enjoyable right from the onset" was a result of Hot Chip "focusing more on song arrangements and structure rather than technology and programming showmanship".