1) Find a spot; these are usually spaced more or less evenly along a profile. Recorder should stand some distance away. Sensor should be "pointed" approximately north (what you point depends on the sensor a small bit). Avoid obvious metal.

2) Press proper buttons (we need to update this at some point for the different instruments used. For instance, on the gradiometer, you hit the button on the little external switch, then recover the measurements with the buttons on the front that allow you to go through stored measurements)

The beginning of the log should include the names and duties of the field party (e.g., "John Jones scribe, Bob Smith reader, Jim Brown GPS"), the id of the instrument being used (including any GPS unit, if applicable), the time zone being used, and the date. A brief summary of the day's agenda doesn't hurt. Which kind of instrument, note sensor height(s).

For each profile, indicate the starting point both with an absolute and relative (locally descriptive) location. Note how you will be spacing measurements out (both your distance spacing goal and means you are using to diot --e.g., pacing, whose pace). Ideally indicate profile azimuth and goal. Might note recognizable points along the way (e.g., summits, road crossings). Should include occasional GPS locations as appropriate. Also not changes in profile orientation.

For each measurement, normally try for 3 measurements in each spot. If things are crazy, perhaps shift off a bit (this can be caused by locally high gradients). Also note measurement reliability if available (varies from device to device--one had a light flash in corner during measurement--5 was good, 1 was terrible)