Add the chicken breasts and broth to the crockpot and cover.
Set to low and cook 6-8 hours.
Remove chicken to the bowl of a stand mixer while still hot. Using the paddle attachment, turn the mixer to low and let the mixer shred the meat. (Do this in two batches to keep the chicken from flying out of your mixer, if needed.)
Separate meat into small baggies (I get 7 baggies worth of meat out of 6 pounds of chicken and each bag has enough meat for one meal for my family of 4).
Place the smaller baggies into a larger freezer bag and freeze until ready to use.
Defrost in the refrigerator or microwave before using.
If starting with frozen chicken, you'll likely need to increase the cook time to 8-10 hours.