gps everything, no markers...on public AND private. Trespassers and thieves are more common than anyone imagines.
I was out this past Saturday. Some guy had been in the area some time in the past 2 weeks...he marked a twig with 12" of orange tape every 10 FEET!!! Right on a 2ft wide, well worn deer trail to boot.
I could see right where he sat; must get lost real easy...walking out of this spot has 3 outcomes..river to the south and west, railroad tracks to the east, county road to the north. (he came from the tracks about 200 yards away)
I'm lucky in that I have a photographic memory of my walks in the woods. I can remember individual trees on single-day trips I took several years ago...I could go and walk almost the exact path I took.
As for markers, the Bright Eyes reflective tacks are the best I've seen in my walks...I very rarely use a light in the dark, but when I spot a tack, and shine a light around...those things light up like a runway.