In this video, Diana, a physician assistant, gives advice on how to increase breast milk supply for breastfeeding mothers. She suggests paying attention to signs such as feeding frequency and duration, wet and poopy diaper count, and a visible decrease in breast size after the baby feeds. Factors like underfeeding, weak suck, smoking, and inadequate nutrition or sleep may lead to decreased milk supply. To increase milk supply, she advises nursing and pumping more often, power pumping or cluster pumping, consuming enough calories (extra 500 calories daily), staying hydrated, and considering herbal remedies and prescriptions. However, the narrator also emphasizes that it's important to remember one's limitations and that as long as the baby is fed, one is doing an excellent job as a mother.