Brown the meat in batches if needed so it sears rather than steams -- overcrowding the pot leads to gray, greasy meat instead of a deep browned crust that builds flavor.
The chili is done when it has thickened enough to coat the back of a spoon and the fat has fully integrated; internal pot temperature should be a steady 200 to 210 deg F during the low simmer.
Prep and chop all vegetables before the meat goes in the pan -- once the beef and sausage are browned, the remaining ingredients go in quickly and you don't want the fond to burn while you're still chopping.
A dark beer like a lager or amber ale works best here; avoid IPAs, which turn bitter after a long simmer.
This chili improves dramatically overnight -- make it a day ahead, cool completely uncovered, then refrigerate; skim any solidified fat from the surface before reheating over low heat. Stores refrigerated for up to 4 days or frozen for up to 3 months.