Poop bags, obviously. You can even subscribe to get the bags dropped off weekly or monthly. We use this for the back yard, and this for outings.
Chuck it! If your pup wants to play fetch, this is definitely a need.
Flippy Flopper. Mia has gone through so many frisbees (and so have I from being a bad thrower), but this one seems to have lasted the test of time and is easier for me to throw as a novice Ultimate Frisbee player.
#raisethewoof Outward Hound sells both a hiking pack and life vest that help Mia stay on the sporty side. They are relatively inexpensive and so far very durable!
“The Spray”. At this point, even the threat of “the spray” will keep Mia in line. Bitter Apple is the best for spraying on boxes or cabinets you don’t want her in, or as a reminder not to do certain things.