Freeze beef for about 30–45 minutes to firm it up, then slice thinly (about 1⁄8 to 1⁄4-inch thick) against the grain.
In a large bowl, whisk together soy sauce, Worcestershire sauce, brown sugar, garlic powder, onion powder, black pepper, salt, smoked paprika, red pepper flakes (if using), and liquid smoke (if using).
Add sliced beef to the marinade and toss to coat evenly.
Cover and refrigerate for at least 6 hours, preferably overnight (8–12 hours) to deeply infuse flavor.
Preheat smoker, oven, or dehydrator to 160–165°F (71–74°C).
Remove beef from marinade and pat slices dry with paper towels.
Arrange meat slices in a single layer on racks or dehydrator trays without overlapping.
Dry until jerky is firm yet still pliable (not brittle):
Dehydrator: 4–8 hours
Oven: 4–6 hours (door slightly ajar to allow moisture to escape)
Smoker: 3–5 hours, low and slow
Test a piece: it should bend and crack but not snap.
Let jerky cool completely before storing.