In regards to the bitters -
bitters stimulate the release of digestive juices, so they are best taken just before a meal or at the start of a meal.
Hv says: I recommend 1/2 dropper full on the tongue before meals. The bitters must be tasted by the tongue to work. Remember to drink a lot of water throughout the day to flush the toxins being released from the liver as bitters also cleanse the liver.
One exception where bitters are not good is in cases where someone has had their gallbladder removed. This can be a problem as the bitters stimulate the release of bile. Since there is no gallbladder to control the release this can cause diarrhea from burning of the intestinal wall. So if the gallbladder is removed then raw ACV would be a better choice.