My hiking shoes starting having problems with the insoles, so I got replacements. However the replacements I have are "Trim to fit."
How do I get the proper shape so that I don't end up with any misaligned or rough edges?
The only technique I use is to take out the old ones, draw round them with a sharpie and then cut out to the inside of that line.
This works very well, and trimming to make sure the line is just removed gives an accurate measure.