Traveling with an infant

I've two international trips coming up. Both are with my infant daughter. The first trip will be without my husband, while the second he'll be with us (thank God). This first trip being Baby's first time in an airplane (and indeed, for many hours!), I want to be as prepared as possible. For all the first time parents out there, here is what I've learned so far: 

• Infants less than 22 pounds/10 kilograms are afforded a bassinet for ease of travel while in the air. This seems to only be for intercontinental flights, however, and basinets need to be reserved in advance. (SOURCE) I had assumed that Baby would get a basinet automatically, but apparently this isn't the case. 
• Many countries require proof that the non-accompanying parents approves of the child traveling without him/her. US Customs and Border Control (CBC), for example, strongly recommends carrying a signed letter from the non-accompanying parent stating "who, what, where, when, why and the parent's contact information." I've also read that it's best to carry a copy of the non-accompanying parent's passport, as well as the child's birth certificate. (SOURCE)
• Sealed, bottled water can be used for mixing formula on the airplane (I had been worried about not being able to carry on my usual - water boiled for 5 minutes). 
• Pacifiers used at take off and landing can help prevent pressure from building up in Baby's ears. If she's not used to that, breast feeding or a bottle also work!
• Not reserving a separate seat for your baby saves money BIG TIME. On this upcoming trip, I'm literally saving around one GRAND. 
• Even babies without their own seat get a baggage allowance :)  KLM, for instance, states that Baby is allowed a carry-on (12kgs max) and check-in (10 kgs max). SOURCE