Summarize the following:
If your child eats solid food, back snacks like granola bars, applesauce, crackers, or Cheerios. Pack milk, formula, or baby food--if this is what you feed your child. Make sure general liquids are under 3.4 ounces so they pass security inspections. However, you should be able to bring greater, reasonable quantities of breast milk or formula through without issue. Just have them out of your bag, ready for inspection, and tell the screening agent what they're for. They may need to test the liquids, as a security measure. You can also buy milk, water, and juice after you get through security. You may want to pack a cover so you have privacy while nursing. You can also use a blanket or towel, though bring your own. A bib will help with messes while eating. Pack washable or plastic bibs when traveling. Bring at least one cloth to use for burping if your baby is still prone to spitting up. Since you probably won't be able to clean your bottles thoroughly during travel, you probably want to bring enough so that you can use each one just once. You can probably get by with fewer plates/utensils, if any.
Pack snacks, formula, and baby food. Consider a cover-up if you are still nursing. Bring a bib and burp cloth. Pack bottles and sippy cups, as well as plates/utensils, if needed.