Be sure that the surface is cleaned before applying graphics. A mildly soapy water solution may be used to clean the surface. For better results, rubbing alcohol (isopropyl/isopropanol) can be used additionally. Avoid using ammonia-based cleaners, as this can cause long term issues with the film and adhesive.
Remove liner entirely and allow marking to drape. Using a firm initial squeegee pressure, begin at top center and work down and outward to each edge of mask.