I've found these factors in particular to be crucial: mash in no lower than 146°F, and hold an extended rest around 160°F and mash off at 170°F; ensure correct mash pH, and acidify wort to pH 5.0 10 minutes before end of boil -- this ensures optimal performance of kettle finings and removal of hot break and lipids; a short, low intensity boil (this is probably the hardest thing to impress on homebrewers, and makes a huge difference in many areas;) rapid fermentation as cool as the yeast can go (this presumes proper yeast handling and health,) and a period of cold storage (29°-30°F) but not too long (a week or three is good.) These points, of all those in the chart from Kunze and quote from Kai posted by BrewBama, are process-oriented and can be applied to any recipe; higher iso-alpha content, malt specification, and such are just as valid, but can't be observed in every recipe.
One further process point: You've noticed that the head gets finer over time, and this is indeed because the CO2 is becoming better dissolved and comes out in a finer "bead." Even if you burst carbonate quickly, it would help to hold the beer for a period of time at serving pressure and temperature before tapping to permit this to happen. Or even simpler, just carbonate over a couple of weeks at serving pressure. The gas will be finely dissolved by the time the beer is ready. I've found this works even better for some reason.