How do you navigate an unfinished attic?
Since my attic requires maintenance on solar vents and a power vent in the end gable, I took 5/8" plywood, divided it into three lengthwise strips and put a catwalk down the center of the attic. As a prior answer notes, use a small rake to fluff the insulation back over to the proper depth when you're through.

This was after a few years of playing Tarzan, catching the truss uprights and gauging where the feet went. Then you get off by two inches in a partial slip (did I mention hanging onto the truss members?) and find yourself staring ceiling repairs in the face. The plywood's cheaper than figuring out how to replace a ceiling with heating cables embedded in its lower surface.