we have a guy come into work that does them professionally, he shrinks the film slightly first before cutting to get it to shape the window, then cuts the film to the edge of the "dot matrix" (rear screen) he then soaks the window in soapy water, soaks the film in soapy water as he's peeling the film off, then fit to screen and squeegy out all water, if any small bubbles appear around edges he uses a hot air gun and squeegy to get rid, if they are in the middle, leave to dry and then use very sharp blade the next day to slice the film slightly and squeegy out again.
hope this helps