BRING SOME GROCERY BAGS IF YOU PLAN ON GOING TO THE MARKET IN LORETO
I know this seems like its not a big deal, well it is. They don't have plastic grocery bags down in Loreto.
They do offer the fancier reusable ones, but they come at a price. Just stuff several plastic bags in your suitcase. While you are at it, stuff a couple trash bags too. Sometimes, the place where you are staying only provides one trash bag.