Finish preparation before the fast part begins
Group ingredients by the work they need. Firm carrot pieces, thin pepper strips, and tender leaves do not take the same time to soften. Pieces should be reasonably even within each group. This is a practical preparation plan, not a single order claimed for every regional stir-fry.
Choose a pan that matches the stove
A wok can be useful, but a stable wide skillet also allows a home cook to make a small batch. Match the pan to the burner and the recipe. Do not heat a coated pan beyond its manufacturer's instructions in pursuit of the very high heat shown in restaurant videos.
Oil should spread across the working surface before the food goes in. If the pan is producing persistent smoke, reduce the heat and reassess. A vigorous cook requires attention and ventilation, not an instruction to push every piece of cookware to its limit.
Give wet ingredients a smaller batch
Mushrooms and other moist ingredients can release enough water to change the pan from browning to simmering. Dry them after any washing or thawing and use a quantity the pan can handle. A smaller batch gives the moisture more room to leave.
Lift a finished component out when necessary, then cook the next one. This keeps a quick-cooking ingredient from waiting in the pan while a firmer one catches up. Use a clean plate for cooked food if raw meat or poultry is part of the recipe; keep raw-food equipment separate.
Let the vegetables and sauce have separate stages
The Nutrition.gov vegetable stir-fry example adds firmer vegetables before pepper, then brings the mixed sauce to a boil to thicken it. The useful principle is sequencing: the vegetables get time against the hot pan before the sauce takes over the surface.
If the chosen recipe uses starch in the sauce, stir the mixture again immediately before pouring because starch settles. Add the amount the recipe calls for and cook it as directed. Extra starch cannot repair undercooked vegetables, and extra liquid can turn a small stir-fry into a pot of sauce.
Taste the assembled bite
Once the components return to the pan, combine just long enough for the chosen recipe and the food's safety requirements. Serve promptly so the vegetables keep the texture you worked toward. Have rice or noodles ready before the last pan stage begins.
Taste an assembled bite before adding more salt. A salted sauce and seasoned vegetables can be quite strong together even if each seemed restrained separately. For Chinese cooking context, read the linked cuisine guide; this article describes general batch planning for a home stove.
Keep in mind
Follow a complete recipe for sauce quantities and any raw animal ingredient's cooking requirements.
Keep the pan within its manufacturer's heat limits, especially with coated cookware.
Match the batch size to the pan, burner, and ingredients.