This is a bit of a purist approach to making burgers. We use the meat grinder attachment to a KitchenAid mixer, and fresh chuck roast, for super clean, tasty and juicy flavor.
If you love burgers, consider reading the book "Fast Food Nation." That's when we decided to start grinding our own beef. It's really very simple to do, and the flavor and freshness can't be beat! Just use meat with a decent proportion of fat (otherwise, burgers won't be juicy). Cheap, tough cuts work very well.
One advantage to preparing burgers from freshly ground meat is that, with proper care, concerns about bacteria / other pathogens from pre-ground meat are essentially eliminated. This is especially comforting for people who like their burgers rare.
We use minimal (usually just salt and pepper and sometimes a touch of dried basil) or no seasoning in the meat.
Step 1: Grinding Beef
Start with 3 to 4 pounds (I usually grind more than I will use in making the burgers, and freeze the rest for use in other dishes, as mentioned in Step 3; grind less if you like) of very cold (chill in coldest part of your refrigerator) chuck roast - about 10-20 percent fat content. Don't use lean cuts of meat, or the burgers will be too dry after cooking; going for juicy grilled flavor here.
Cut meat to fit the grinder. Here, it's cut into 3/4" - 1" by 1/2" thick strips. Note the amount of fat present; purchase cuts of meat with a similar appearance.