You may find it useful, if you have one, to use a steamer to help get the film to stick down in areas where it requires some stretch. This can often occur if you need to get the film down in an air vent or light well for example.
Although the use of steam is not mandatory, having a steamer is beneficial for such tasks. If using heat, ensure it is applied lightly to allow the material to stretch without weakening it.
By employing heat or steam, the material can become more manageable and easier to work with, steam not only warms the film but it keeps it wet with water which is a form of weaker tack solution, this facilitates the fitting process. If needed, leaving the material to dry out and revisiting it later is a viable approach if a steamer isn't available.
Patience is emphasised in allowing the material to dry and settle for a better outcome, ensuring a neat and even finish. Keeping an eye on the material periodically and making adjustments as needed contributes to achieving a successful fit. By maintaining alignment and taking necessary time for the material to settle, the fitting process can be smoothly carried out.