Proofreading, part 8

When I'm proofreading my writing for the first time, there are two questions I'm asking regarding each of the 304,805 letters: is the letter there, and is the letter kosher?

The process goes like this.

With a sheet of freshly-written Torah in front of you, you find your place in the tikkun and look at it to see what letters ought to be written.

Carrying those letters in your mind, you look down and find your place on the klaf, and compare the letter string in your mind to the letter string on the klaf.

If they don't match, fix it.

For instance, this is just wrong, but I didn't realise it at the time. It ought to read שמנה מאת שנה.

Then look back up and find your place in the tikkun, and repeat.