Start with the formula instructions
Pressed and loose powders do not load onto a brush in exactly the same way. NARS advises softening the surface of its pressed Light Reflecting Setting Powder with repeated brush swirls on first use.
Control the amount
Begin with a small amount rather than a full-face coat. Work on the areas where you want a more set finish, then assess the result before applying more.
Use a deliberate placement
A smaller brush can help keep powder away from areas where you want visible radiance. Blend your base first so you are not trying to repair uneven coverage with extra powder.
Keep a simple comparison
Try your routine with less powder on one occasion and note the finish you prefer. Powder choice and placement are personal; a tutorial is a starting point, not a guaranteed result.