These are up front, directly behind first-class, and will give you a little extra floor space. When you make your reservation tell them that you are traveling with an infant. Check with your airline to see if you car seat will fit in the bulkhead seats. Choose a low-volume flight. Call your airline and ask which flights are usually the least crowded.
Extra space makes for a more comfortable trip.
Choose your carry-ons wisely. Overhead storage space is at a minimum. Check oversized or odd-shaped luggage. Arrive early at the airport. Once you're checked in, ask if the airport has a special play area for kids.