Here’s a picture I took as I was just starting to mask up for putting the white line transfers on around the grey window section.
The lines from Fox’s as water slide transfers as a set of lines and corners (I used the smallest corners in the set. Once cut out with a scalpel you soak the transfer in warm water with a drop of washing up liquid for about 30 seconds before applying. The bottle of Micro Set is to both help the transfer to slide a bit and once set helps to stick better.
The plan was to have a straight line of masking tape to use as a reference line.