[Hull_chipper]

I prefer to use a fine drill bit instead of the fibreglass pencil. Get one that fits into the via & rotate it gently a few times. This provides a great key for the solder, but most importantly, means you are not uncovering the tracks (which is possible when you scratch the entire area with a pencil).

You can then safely & confidently lay the rest of your wires flat against the tracks without fear of bridges. Its also very helpful when the vias are totally oscured with paint!