Some pipettes are built "to deliver", by filling to the line, and then clearing out the pipette with a small puff of air.

Others are not built TD, and you need to be clear which type you have if you want to be both precise and accurate!

Regardless, develop a standard way to measure, and then be consistant, and it won't matter if you are not actually measuring an exact amount when you fill the pipette.

Oh, if you're like me, you won't like the glass pipettes, and will eventually find plastic ones, so you never have to worry about breakage.