Advanced Carpentry Measuring

There are a couple of levels of carpentry such as framing houses, hanging siding, etc. Where it really doesn't matter is if you are off by a 16th of an inch. Then there is a medium level where you have to be accurate down to a 32nd of an inch. This would include doing indoor trim. Then there is the top quality craftsman. To him a 32nd of an inch would be huge. This is what is needed to be able to create cabinets, hang doors, build dresser drawers, etc..
The way in which such a true craftsman views the tape measure is totally different from the way in which amateurs might look at it. Many people are content to measure something to the closest measurement on the tape measure. A true craftsman will take that same measurement and say to himself that it is 9 foot 7 & 3/16 plus space center. This would mean that it was dead center of the space that is just beyond the 3/16 mark on the tape measure. Another measurement might be 6 foot 5/8 inches minus. This would mean that while it was touching the 5/8 inch mark it was only barely touching the short side of the mark. See a true craftsman will not only split every mark on the tape measure into 3 being plus minus or dead center. They also split the spaces between marks into 3. Getting their actual measurements down to about 1/192nd of an inch. With this sort of precision, it makes it easy to make things fit inside each other, and look right. As well as opening and closing right. If you don't use this sort of precision then your doors will swing themselves open, when you don't want them to, simply because you were off 100th of an inch in the wrong direction.
To top that, he tries to keep his pencil ultra sharp when doing fine cuts as this will change the average pencil mark which is generally 1/8 of an inch wide to where it is only 1/16 of an inch wide. So he will measure once to make his mark. Then measure again to see exactly where in that mark his measurement falls, (whether it is plus, minus, or dead center of his mark). He also uses the second measurement to double check the first.
When a craftsman is doing fine work, he generally likes to do all the steps himself because this makes it easy to remember the plus or minuses accurately instead of trying to describe them to someone else. Then when he goes to cut he takes and places the main bulk of the 1/8 inch cut most saws make in the scrap portion of the piece. Only the fine edge, 1/100 of an inch of the saw, will touch the part of the mark that he intends to cut off. Carpenters that become accustomed to using the extra precision will find out that all of their work turns out better.