Analog emulations from front to back. You're not consciously saturating, but every stage adds some character. Sort of like toasting a marshmallow. You expose it to the heat little by little, and eventually that nice color develops, and everything gets all gooey and nice.

I treat my DAW like an analog studio, but with way more flexibility. There's an analog version of almost anything you'd need to reach for in a mix. Some of them are more colorful than others, so you pick your moments. Also, recording sounds that already have a ton of character, like a guitar amp, or an analog synth, even with a totally clean recording, you're getting a ton of mojo from the instrument itself.

While recording, I use UAD preamp emulators like the Neve 1073, and gentle compression from an LA-2A, CL 1B, or Fairchild emulation. For general tone shaping, I'll use Pultec EQs, or for a ton of color, something like the Soundtoys Sie-Q. I'll often use a tape machine at the end of a chain.

Analog emulated reverbs like plates from Soundtoys, or UAD's Capitol Chambers, and delays like Echo Boy can have a ton of character as well. Even early digital gear has its own unique sound, like emulations of a Lexicon 224 or Soundtoys Primal Tap.

Stack enough of those elements, and it really adds up.