When I collect line features I usually do it vertex by vertex, meaning I collect a point everywhere the line changes direction. There are options for collecting as you walk and for collecting point by point. It depends how important the accuracy of each vertex is, the geometery of the feature you are collecting, and what sort of editing you have to do with the data when bring it into Arc. For a lake delineation I would just walk around and collect points at a certain distance or time interval. For sewer lines I would get a point at the beginning and one at the end of the line, since they should not turn. So the sinuosity of the feature plays a part I guess. You can try both methods in one data collection session and you will see a very noticeable difference in the outputs. This would also give you an idea of the effect averaging has on GPS point collection. When streaming a line each vertex is one point collected, so you can see how the points differ as you walk a 'straight line.'
Hope that helps!
Sol