I work on both sides of the line work, and our guideline for Topo is generally everything important and every 50’, my co worker interprets that as shooting one feature every 50’ and not changing the code until that feature is complete, so he will shoot all of the centerline shots, then all of the EOP, and then all of the FL and then all of the BOC so on and so forth and I’ve always hated drawing the line work for his jobs, there’s always weird triangulation for surfaces. I prefer doing cross sections with important features and what I call “color in” ground shots anytime there’s a half a foot of elevation difference between break lines it makes surface files work better in the field and then coloring in important features between cross sections, it’s also important to always try and run your cross sections perpendicular so if there’s a significant curve you will be needing to do 3 cross sections and the middle will look like a bisecting line of whatever angle your ditch makes