Heat the buns just a bit. Not toasted, just warm.
Add a small squirt of mustard and ketchup to the top bun.
Add a pinch of the diced onions and 2 slices of dill pickles.
Add a slice of cheese to the bottom bun.
Place a beef patty on the bottom bun.
Add another piece of cheese atop the beef patty.
Add the second beef patty.
Add the bacon atop the second patty.
Cover -- carefully -- with the top bun (or, do what I do, and add the bottom to the top and then flip the whole thing).
In a nutshell -- you want: bottom bun, cheese, meat, cheese, bacon, condiments and top bun.