1. Play before your Rover can cause trouble not after. If you start a play session after he has done something he's not suppose to it will only reinforce the bad behavior.
2. Check the weather. If its going to be extremely hot or nasty out, get your play time done early or try some indoor games like hid and seek. Hide yourself some where in the house then call your dog and wait for him to find you. Then reward with lots of love.
3. Don't forget if your taking him to the local dog park take along some plastic bags for cleaning up that which comes naturally. Nothing recks a nice dog park faster then lazy people who don't take care of their doggies messes.
Now are you ready for some fetch?