Sawing accurate cuts in wood is all about using the proper saw with proper technique, and it often takes repetition and experience to get a feel for things. Luckily, there are a few tricks to help those of us who to achieve good results without years or practice.
In this recent video, Chris Schwarz demonstrates his nibbling method, where he establishes a kerf at workpiece corners before “swallowing the whole giraffe.”
This nibbling technique seems built upon the sawing technique most people already find natural – to start at corner where two faces meet.
Explanation via Popular Woodworking