I haven't done any real training with Gunnar (who is almost 11) for a couple years. He's in "maintenance mode". I still make him do down/stay and then throw the ball, or have him stay and I'll hide it and have him search, other things like that, but that's not really training, it's using what he already knows. He never needs correction on it so it's not even brush up work when we do it, it's just what he knows is expected of him.
Of course, having a 6 month old pup more than makes up for it!