Milk secretion from breast happens , when there is stimulation from brain. Baby's suckling stimulates mothers brain and in turn milk secretion.
So the first step is to keep the baby every time when it cries for feed to breast. Allow the baby to suckle though there is no milk coming, and then give any other feed. If u keep doing it, in the subsequent feed times, milk will gradually start coming.
Next Steps
You can take Tab. Motilium(Domperidone) one in morning one in evening for 5 days. Take tablet only if the above mentioned method doesn't work out even after one week of trying. This tablet might cause some loose motion as side effect rarely.
Health Tips
You can take all the food items without any restriction mainly natural foods. Add Zeera(cumin)to many of the food items you take. That will increase the breast milk secretion to some extent.