This is important, so I need you to close all the other tabs on your browser and quit all the other apps on your phone.
Okay. cracks knuckles
First, you need good bread. It doesn't need to be fancy, but it should be fresh. Your grocery store's bakery will sell crusty sandwich loaves. Pick one in your preferred size and shape.
Second, you need fat. Butter, mayo, oil, avocado, whatever you like. No Miracle Whip shaming here. But you NEED something to smear on the bread. It's for flavor, yes, but it's mainly to keep subsequent ingredients from making the bread soggy. It's a moisture barrier. If you skip this step, I don't know what else to tell you other than we're not friends anymore.
Third, add meat now if you're a meat eater or the most robust vegetables if you're not. The only meat I eat is turkey, really, so that's what I go for. But this is all personal preference.
Fourth, put cheese on top. Muenster is the obvious choice, but it's fine if you prefer something else, even though you're wrong. People overdo cheese. The amount you just put on there? Take half of it off. You probably overdid the meat, too, if you're American, but I'm not trying to bust anyone's ovaries over that so close to July 4th.
Fifth, layer fresh slices of tomato and cucumber. I like to slice them into half-circles and alternate down the length of the sandwich. It adds variability to the bites. Want more vegetables than that? Then put 'em on there. You don't need my permission, I'm not your mom. But if I was, I'd tell you how proud I am of you. This is a good time to add pickles, too, if you're a pickle person.
Sixth, we're going to make a janky slaw. People get lazy and toss leaf lettuce on sandwiches all the time. I get it, but we can be almost as lazy and make still make a better sandwich. Shred some lettuce and grate some carrot. Add some sprouts and onion if you're feeling frisky, then toss everything into a bowl. Now add a couple drops of olive oil and as much mustard as you'd like. Season that with oregano and basil to taste, then toss. Lay that shit on top of your other veggies.
Eighth is optional, but if you're not onboard with this step you may want to consider an inpatient program. Chips. "Crisps," if you're Bri'ish. You fucking heard me. Regular potato chips are fine, but we've come so far already that such a half-measure is kinda disrespectful if you really think about it. I'm a fan of barbecue. Wtf are you doing?! Don't lay them on there whole. Christ almighty, you gotta smash them up. Not so small that they lose their crunch, but small enough that they'll conform to the contours of the toppings underneath. The amount of potato chip you put on is up to you, but I think an absurd amount is generally appropriate.
Lay on the top piece of bread and press it down. Don't eat it yet, though! It's gotta rest so the flavors mingle a bit. If you've got butcher paper or parchment paper handy, do what all the sandwich shops do and wrap it up. Do it nice and tight. You don't need to wait long. Maybe 10 minutes. Once your sandwich is well rested, NOW you can shovel it into your gaping maw like some kind of starving animal.
Or you can do PB&J. Idgaf, it's your lunch