I wanted some decals to complement the graphics I've put on the plane. I won't use them all for this project but you can only print to the sheet once. Three coats of clear Krylon should seal them just fine.
First step - cut out the decal.
Next step - a little Windex to clean the covering.
After placing the decal in a dish of water, I dab a bit of water on the covering, take the decal out and slide it into place. After positioning, some careful blotting with paper towel and it's done. I let decals cure overnight before flying.