In the middle of the tortilla, layer the ham and salami. Sprinkle the cheese over top. Add lettuce, tomatoes, and red onion. Drizzle with salad dressing to taste.
Roll up like a burrito. Serve with extra dressing on the side.
Notes
It will help if you have room temperature or even slightly warmed tortillas. They crack less and tend to stay rolled when they aren't refrigerator cold.
Don't overfill the wrap -- I'm looking at you, Chipotle -- or it will be too hard to keep closed. Go for thinner tortillas so that you don't feel like your filling to tortilla ratio is too skimpy.
To make it packable, leave the wrap "dry" and serve the dressing on the side.