We took our daughter at 10 months to Bali. It went pretty well. I cannot agree more with bringing any meds you might need and a thermometer. Our daughter ended the trip with a double ear infection (we didn't know what it was the time) and we had one bottle of tylenol that leaked on the flight over as the lid wasn't on tight enough. She handled the flights well, but her fever had me freaked out.

I always had a small bag (backpack, etc) when traveling with my babies of just their things - clothes, diapers, wipes, toys, etc. You should plan for them to have extra spit ups, blow outs or accidents on the plane as it happens almost without fail. Also, if the baby is on formula, buy water at the airport and take it on the plane. I wouldn't depend on the flight crew for water for the baby. Since we were in Bali, I brought all the food she needed as I didn't want the food to upset her stomach.

If you can get away with wearing the baby, it is best for all. We had a Boba and it was awesome. It depends on the baby, but for us, a slow day was best. If we had a full day of things, it wasn't fun.