Sweet little dots.

Yes, I made all the dots in the background by hand.
And, yes, I'm a notorious liar.
Now, seriously: Screentones applied by cut and paste on the original art while waiting in line to use the scanner. No digital faking here.
Sitting at your drawingboard with your scalpel, cutting out screentones and applying them to the artboard is just pure therapy for the stressed soul. You should try it instead of seeing a therapist. Just ever so relaxing... Hmm, might as well go cut some just for fun.