A great way to keep your dog physically and mentally stimulated is by teaching them new tricks. We are sure that you have already built up an impressive repertoire, but there is no limit to the number of tricks you can teach your dog. Just remember to keep practicing them!
We have already discussed a variation of this game, but it can be adapted in an infinite number of ways. It is such a classic, but still a lot of fun. One way to do this is by playing with two balls (or sticks or whatever you play with). Throw them one, then when they come back, throw the other one. This will cause them to drop the first one and chase after the second.