For me it's all in the wrist and knowing what you want them to look/taste like.
I'm not very good at explaining much (nevah even DREAMED of being a teacher as a child, LOL) so here is how CI explains it:
Cooks' Illustrated wrote:
Serves 2
It's important to follow visual cues, as pan thickness will affect cooking times. If using an electric stove, heat one burner on low heat and a second on medium-high heat; move the skillet between burners for temperature adjustment. If you don't have half-and-half, substitute 8 teaspoons of whole milk and 4 teaspoons of heavy cream. To dress up the dish, add 2 tablespoons of chopped parsley, chives, basil, or cilantro or 1 tablespoon of dill or tarragon to the eggs after reducing the heat to low.
Ingredients
4 large eggs plus 1 large yolk
2 tablespoons half-and-half
1/8 teaspoon salt
1/8 teaspoon pepper
1/2 tablespoon unsalted butter, chilled
Instructions
1. Beat eggs, yolks, half-and-half, 1/8 teaspoon salt, and 1/8 teaspoon pepper with fork until eggs are thoroughly combined and color is pure yellow; do not overbeat.
2. Heat butter in 10-inch nonstick skillet over medium-high heat until foaming just subsides (but should not brown), swirling to coat pan. Add egg mixture and, using rubber spatula, constantly and firmly scrape along bottom and sides of skillet until eggs begin to clump and spatula just leaves trail on bottom of pan, 45 to 75 seconds. Reduce heat to low and gently but constantly fold eggs until clumped and just slightly wet, 30 to 60 seconds. Immediately transfer eggs to warmed plates and season with salt to taste. Serve immediately.
Step-by-Step
Unscrambling Perfect Scrambled Eggs
To get big, fluffy, tender, and rich-tasting curds, we experimented with every element of the process until
we nailed the right formula.
8 EGGS PLUS 2 YOLKS adding yolks not only enriches the egg flavor, but the extra fat and emulsifiers raise the coagulation temperature to stave off overcooking.
HALF-AND-HALF offers more rich-flavored fat than milk but also contains enough water to generate the steam necessary to make the eggs puff up.
10-INCH SKILLET Trading the usual 12-inch pan for a smaller 10-inch one keeps the eggs in a thicker layer, thereby trapping more steam and producing heartier curds.
DUAL-HEAT METHOD starting the egg mixture over medium-high heat creates puffy curds; turning the heat to low once the eggs coagulate ensures that they won’t overcook.
Technique
Turn It Down
When your spatula just leaves a trail through the eggs, that's your cue in our dual-heat method to turn the dial from medium-high to low.
Recipe Testing
Scrambled Egg Extremes
The best puffy scrambled eggs aren't hastily cooked over high heat. Nor are they gently cooked over low heat.
RUBBERY Blasting the eggs over higher heat gets breakfast on the table in a hurry—but produces dried-out, rubbery curds.
Keeping the heat low might prevent the eggs from overcooking, but the result will be loose, tiny curds that look like lumpy custard.
This method comes closest to how I learned to make SE.
HTH!
