Fresh-drop indicators: green acorn caps still on the ground, unbroken acorns half-buried in leaf litter, deer pellets and tracks fresh in the area. A productive drop tree near bedding will have visible disturbance — leaves kicked back, acorn shell debris.
This is one place running cameras on hunting access trails (rather than deep in the woods) helps. Deer routes to and from drop trees concentrate where bedding meets food, and you can monitor without bumping. Pair with current state mast reports.