Well, this is one of the reasons why Prop 64 is on the ballot this year, which is to ensure higher level of quality and regulation when it comes to marijuana products, including edibles.
It is widely known that the dosing within edibles can vary as much as 5-10% in regards to the THC content. I think when you are thinking about quality, there are some things that come to mind:
-high quality extraction/oil being used within the product
-high quality ingredients
-zero pesticides and lab tested
-consistency with dosing ie no ‘hot spots’
Assuming these are some of the qualities you mean, it is fairly easy to find a great edible these days. I think it often starts with the dispensary, if you have a reputable dispensary, they often carry the bigger brands. The bigger brands are professionally packaged and have comprehensive labels. They often will tell you what kinds of ingredients they use i.e., gluten free etc. Bigger brands will also tell you on their websites what lab they use for testing.
I would never ever ingest an edible that was not professionally packaged, you have no idea what you are getting.
Some professional brands I love are Auntie Dolores, Kiva, MoonMan’s Mistress & Defonce.
I am not a doctor and this represents my opinion only. I hope this helps!