What is the best way to measure blood pressure?

Good question!: BP should be measured in the sitting position after at least 10 minutes of inactivity, at the level of the heart, on both arms for at least two-three times and the measurements averaged. The subject should not have smoked or eaten the hour before, be relaxed and an appropriate-size cuff used for the body size. Classical mercury sphygmomanometers are unsurpassed. I know this is not adhered to.