On the assumption that you are not flying first or business with kids (you were probably you would not read this post) your alternatives are quite limited but in any case few seating tips:

Sterilized zone – if you are 3 try to find tree seat row, if you are for look for the four seat row or double dual seats. It is much easier when your kids puke on the family members rather than on the grouchy woman on the right or the businessman in the middle.

First row after the toilets or business class are suitable for kids (not only babies) there is more leg room and easier movement between the sides. You will get these seats if you are flying with babies and using a cradle.

Prefer not seat in the last row before the toilets usually the seat will not go down and it is more crowded row.

Exit row, which usually counted as the best seat in economy class are not allowed to kids. If you got it by mistake replace it on the check in because the steward/ess will not allow kids to seat and will replace you and the kids with available seats

Ask for pillows and blanket as you board to the plane and try to build a warm nest for sleeping environment

• Early check in – Cradle seats sometimes are  distributed by first in first get
• Warm clothing even if you are flying to the Caribbeans – it is cold in the plane
• comfortable clothes – No babies suits or fancy dresses
• Diapers- the more the merrier – at least double than usual
• Toys - preferred familiar that make them feel at home
• Home blanket, doll, sheet  – to help them fall a sleep
• pre-moistened towellette for kids – you will thank me for this tip
• Gift or surprises – For the crises
• Closed cap with Straw or bottle with straw – to drink when no beverage is given
• Portable DVD – with familiar movies or shows, sound fancy but can be a life saver forthe flight and also for long car drives abroad