Well, my fish do come out if I sit still, or feed, so I don't have too much to complain about. Guests like to move a lot, and point, etc., so they spook them.
My only long term hider is a single assassin snail. I thought that sucker was long gone, but I always wondered where its shell went since it is colorful and not tiny. I saw the top of its shell peeking above the sand last week, and it is alive and well, which explains the slow but steady appearance of empty ramshorn shells in the tank.