The art of concealment is to work on SSSSM- Shape, Shine, Shadow, Shilouette and Movement.
Sticking bits of foliage in your combat helmet, webbing or over your Main Battle Tank is as much about breaking up the shape of the thing to be concealed as making it blend in to the background. Camo nets with lots of scrim, snipers ghillie suits, scrim nets over heads and shoulders, disruptive paint pattern or uniform patter are also to disguise shape
Camouflage cream/ paint for combatants and hessian over glass is to reduce shine (Regimental Seargeant Majors go apeshit if you have mucky boots on parade. Likewise, they go absofuckinglutley ballistic if your APC is gleaming and shiny on the battlefield. You can't win against a proper RSM).
Hessian rolls on vehicles that are deployed to hang down to the ground over wheel arches and between wheels or skirts that conceal the area between the top of tank tracks and the chassis are to hide areas of unnaturaly shaped shadow.
Not driving or walking along ridge lines, crossing ridge lines/ hill tops in a standing position etc are to reduce being shilouetted against the sky.
Reduced movement reduces the chance of detection. Alien stillness does so as well. A bush moving in an otherwise still environment will likely be investigated as a potential fidgety squaddie. A completely static area in an otherwise windblown woodline will likewise be investigated (or subjected to probing fire) as a possible enemy.
There is a lot of thought and skill that goes into being a Rough, Tough, Hard to Bluff, Lean, Mean Fighting Machine.