Remember to be polite and always keep your cool when dealing with airport staff, as they tend to feel more inclined to accommodate someone who's treating them with respect. A good TIP, bring a box of chocolate and give it to the flight attendants this nice gesture will reward you benefits possibly even upgrade to first class ;)
Since many gate agents and flight attendants may be unaware of the official policy regarding musical instruments, it's important that you have a copy of the official rules printed and ready.
It's advised that you pay extra for priority boarding so that you can make sure to find a space for your instrument before the overhead luggage racks fill up.
Some planes may have an additional closet on board for extra storage. This varies depending on the size of the aircraft, but there's certainly no harm in asking a flight attendant if your instrument can be stowed there for the duration of the flight.
The recent US Department of Transportation ruling is a huge step in making travel a lot easier for musicians. Supplementing these rules with a few extra precautions means that you can now confidently and comfortably take your music abroad without having to worry about the safety of your instrument.