This instructional video demonstrates the correct way to measure and place electrodes. In a clinical setting, with a medical grade tDCS device (Soterix), a subject is measured for electrode placement on the primary motor cortex. The dorsolateral prefrontal cortex region is also shown. This is the first time I’ve seen the video on Youtube (making it easy to share). Previously it could only be found here, where an associated pdf which includes illustrations is also made available.