Tools needed are steel checkering files in whatever lines per inch you want to use. These are expensive.
These files cut a series of grooves in the steel, and when filed at a crossing angle make checkering.
You'll also need a triangular needle fire, a wire file "card" or brush to clean the files, some chalk to chalk the file to prevent chips from sticking in the file, a good light, a small adjustable vise, and a magnifier visor like the Opti-Visor in whatever focal length you like.
A guide device is nice, but it's only an aid to get the checkering started. It's no substitute for your skill in keeping things straight.
Level of difficulty is high because this is a pure hand and eye skill that takes time to learn and perfect.
The way to learn and develop the skill is to buy some steel 3/4" round bar stock to practice checkering the front of frames, and some small square bar stock to practice checkering areas like slide stops.
Buy the files and most other tools at Brownell's.
http://www.brownells.com/.aspx/cid=0...eckering_files