My best buck sign for hunting mature deer is/are does and signpost rubs.
The signpost are the big year-after year rubs. A signpost hit last year means more to me than a bunch of 1-2 inch rubs from this year. I don't hunt the signpost rubs, but they are one of the best clues to perennial buck travel patterns.
I kill my older bucks under 2 general conditions - perennial buck travel patterns and doe family groups.... when I talk about these buck travel patterns I mean travel patterns used for 20+ years.... these get used by generations of bucks and are gonna be bigger picture than you can figure out 90% of the time, you just try to figure out a bit of the pattern. If you are hunting under a thousand or two thousand acres you are just seeing a tiny portion of the big picture.
The second way I kill them is hunting does, hang around the does long enough and it'll come together. The tricky part is being around the does and not screwing up the situation by getting caught or changing their pattern. Look up Heisenberg's Uncertainty Principle
. Something I learned about back in undergrad quantum mechanics class.... but applies equally well to hunting around does. The upshot is you can't always accurately figure out where the does are gonna be because your presence has a tendency to upset the system.
You have to be crafty to get by with it. One strategy I like is coming into the stand later in the morning... let the does go by at first light without being there on stand to get caught. Then I go into the stand a half hour after daylight to catch the cruising bucks. If I could only hunt 1 hour a day in the rut it would 830-930 am. I've killed a very high percentage of my mature bucks then, cruising for does or with does.
IMO spending too much time on stand is worse than not enough.... your presence messes things up, and getting busted by non target deer saves more big bucks than anything since scentlock suits.
R