How to pull an espresso, at home

Most espresso advice is intimidating. Here's the version that fits on a postcard.

The five variables

1. Dose — 18g in, 36g out. Get a scale.
2. Grind — finer than table salt. Adjust until the shot pulls in 25–30 seconds.
3. Tamp — 30 lbs of pressure, level. Pressure matters less than level.
4. Temperature — 93–95°C. Most machines default fine.
5. Time — 25–30s from button to drip. Outside this window? Adjust grind.

That's it. Everything else is fine-tuning.