If you have a gas grill, make sure your gas tank isn't nearly empty. Seriously. Can't even tell you how many times we or a friend has had to run out for gas. Preheat a charcoal or gas grill for direct grilling over medium-high heat for about 15 minutes.
In a large bowl, mix together the beef, onion, garlic, salt, pepper and Worcestershire sauce. Form the mixture into 4 patties, each about ¾-inch thick with an indentation in the center.
Grill the hamburgers directly over medium-high heat, turning once, 3 to 5 minutes per side. Check for doneness by cutting into a hamburger near the center or testing with an instant-read thermometer. For a well done burger, no pink should show on the inside, and the internal temperature should register at least 160°F on an instant-read thermometer. If making cheeseburgers, place a slice of cheese on top of each hamburger during the last 3 minutes of cooking.
If you want to get fancy, during the last 2 to 3 minutes of cooking, toast the hamburger buns, cut side down, on the grill. Serve the hamburgers on the buns with as much guacamole and other toppings as you desire.
Don't forget to make your own burger buns.