Select the appropriate substitute based on your recipe needs (vegan, baking, or storage).
Prepare the substitute by mixing or whipping as required (e.g., rehydrate dried egg whites, whip aquafaba).
Apply the correct ratio for the substitute compared to meringue powder; adjust sweetness or stabilizers if necessary.
Check the texture and consistency before adding to your recipe, ensuring stiff peaks or desired stability.
Use immediately for fresh egg whites or store dried options properly for longer shelf life.