Rob Cosman's Sharpening Rule
The most innovative technique in plane sharpening over the last 30 years is the "ruler trick" by my good friend, David Charlesworth.
Traditionally, a sharp cutting edge is achieved by honing the back of your plane blade until it is dead flat (this takes a while), then you hone the primary bevel to achieve a razor sharp edge.
David Charlesworth introduced his ruler trick to save significant time while still achieving a razor sharp edge. Instead of flattening the whole blade back, he places a thin ruler on the stone raising up the blade about 1 degree so he just hones the leading edge, not the whole back. David's "ruler trick" works great and I always use it.
You only need one thing - a small thin ruler. We have our 8 inch sharpening rules custom made without ruler etchings to allow plane blades to glide smoothly across the rule when executing the "ruler trick".