I don't add anything to the ground beef. They'd taste like meatballs with eggs and breadcrumbs in them.
I have a device that was my mother's to make burger patti's. You fill it with ground beef, then twist its handle, and voila! perfect patti.
I wrap them individually in plastic wrap, then foil, and freeze them.
If you can't find a patti-making device or don't want to be bothered, you can buy them pre-formed from the meat case at the supermarket. The price per pound, though, is usually at 50 cents more. I don't think it's worth paying that.
Yes, you can cook them frozen. I move them from the freezer to the refrigerator a half-hour or so before I'm going to cook--so the seasonings stick.
I season them with salt and pepper or McCormick's Montreal Steak Seasoning on both sides before cooking.
A tip--cook the first side until the top side becomes covered with blood, then flip it (once). Cook until the other side looks equally browned.