For starters, always know where your CBD comes from. Quality brands will provide third-party test results for each of their CBD batches. Lab reports should show the CBD is free from heavy metals and pesticides, and the product has as close as possible to the amount of CBD the label claims.
Additionally, look to see what type of CBD is in the product. CBD can be Isolate, Full Spectrum, or Broad Spectrum. Isolate or Pure CBD contains only cannabidiol and no other cannabinoids. Full spectrum CBD will contain THC and can only be purchased in states with medical and recreational laws around THC.
Broad spectrum contains other cannabinoids along with cannabidiol, but removes the THC.