Rice cereal time, ftm, any suggestions.

Hey fellow moms, my baby is 4 months old and I'm kind of lost on how to start rice cereal feedings. At our last appointment, the pediatrician said we should mix the formula with the cereal and spoon feed him in the morning. She suggested we make the consistency similar to yogurt, so I attempted it today and it was too watery. Needless to say, he spit it right out. Any suggestions would be appreciated.