Well, I’m coming in very late, but here’s my two coppers:
I agree with those above who have said “don’t overdo it”. I know there are plenty of people who love worchestershire sauce and onion soup mix and the like on their burgers, and that is fine for them. To me, such things make the burger taste like a steak. When I’m having a burger, I want a burger, not a steak. So, all I season my meat with is 1.) onion salt, and 2.) pepper. Nothing more is needed.
As said above, make big patties, because they’ll shrink. Make 'em thin, too, because they’ll puff up.
Get your grillin’ grate hot before you slap 'em down. I shoot for about 550-600 degrees, for a good initial char that helps hold the patty together. After getting a good initial sear, the heat goes down and I flip frequently until my burger is well done, which is how I like it. “Frequently” means about every minute to minute and a half. And in the final minute, put the cheese on it while it’s still on the grill so it gets good and melted. You can toast the buns some during this time too.
Here’s my “rotating technique” to get everything cooked nice and even: imagine you’re grilling eight burgers. The layout is four wide/across, and two deep. When it’s time to flip, I start on the left side and slide my spatula under the burger at the rear of the grill. Keeping the patty on the spatula, I return to the front and use the front edge of the spatula to slide the front burger to the rear burger’s former spot, without flipping it. I then flip the burger still on my spatula, the one that came from the rear of the grill, into the spot just vacated by the front burger. Then, I do the same thing to the next burger column, and so on.
With that pattern, I ensure that every burger gets flipped after a fair time on the heat, and every burger travels around a bit. I find that keeping things rotating like this helps ensure that all burgers cook evenly, instead of some getting more heat than others by virtue of being at the front or back of the grill.
So, there’s some of Max’s grilling tips. Hope they help some.