To extend the life of the railing fasteners, the author fastens the top rail to the guard posts from below.
Between each guard post, he installs a 2x4 subrail to lock the posts firmly in position. This is required to resist the tension the cables transfer to the posts.
To streamline the install, he places bar clamps to hold the supplied drilling template to the posts with the bars facing away.
Fastening is easier with bars of the clamps facing away from where he needs to work with the template.