There is one more thing you can do before wasting silver on nails for signs. I know buying nails is a pain when a noob.
Go to the town, zoom to a height where you can get a good view of the town but still get good details. Take a screen shot.
Return to the town a whenever you have time, and take another screen shot. Compare the screen shots and look for evidence of activity.
If you see activity, then do the sign. You don't have to waste silver on nails this way and leave your homestead secret out in the wild.