A well-trained infantryman knows how to position, dig, brace and camouflage a variety of fighting holes used for different purposes. Individual or crew-served weapons? Covered and concealed firing positions? Overhead cover? Mutual support to other positions with interlocking fires? Staked boundary and FPF references? Drain and grenade sumps? WWI and WWII infantrymen were very well trained in the practice, and "digging in" is still second nature for Marine infantrymen. Digging both hasty and prepared positions is a practiced art; the more you do it, the quicker and better you get...