I'm sure this is an old one, but it was new to me and comes courtesy
of Tom Silva of ATOH fame.
Rip a piece of ply (1/4-1/2 thick), 4"W x Length desired.
Rip a piece of 1/4 ply, 12"W x Length desired.
Glue 4"W onto 12"W with about 5" on one side, 3" on other based on the
width of the sole plate of your saw.
You want to have 1/4" material that will be cut by blade.
When glue is dry, place saw sole plate against 1/2 piece and rip the
Turn ply end for end and rip again using the opposite edge of sole plate.
You now have an edge guide that measures directly onto the piece to be
cut, that also eliminates any necessity of accounting for saw blade
As they used to say in my neighborhood, "Wear it in good health."