First, ensure the mould surface is suitably sealed (porous surfaces such as wood or or plaster must be sealed before they can be used as a pattern or mould), clean and free from any contaminents.
Using a clean lint-free cloth apply a reasonable amount of PVA Mould Release Agent to an area of the rag. The cloth should be well wetted by the PVA in this area.
Wipe the rag over the surface of the mould in a smooth deliberate motion. The PVA has a dark blue die to help you to see where you have been. Ensure you coat the whole surface of the mould with a thin blue film, paying particularly attention to tight corners.
PVA is only ever applied in a single coat. Do not attempt to apply a second coat as this will simply remove the first coat as you try to apply the second coat and result in a more uneven surface.
Allow the PVA to dry fully (around 15mins) before you begin laminating.
When re-using a mould you should remove any traces of the PVA using water and clean thoroughly before re-applying PVA.