Well, as a frequent flyer I always recomend to travel light. You may never know when you can shop for new clothes when you arrive to your destination. Ofcourse always secure your valuables.
Have a handy travelers pouch wherein you can put all your supporting documents(passports, plane ticket, money, proper identification) that are needed for inspection in a very accessible and easy way you can find it and always keep it safe.
I recomend that you buy a Samsonite travelers case (Php700-800) it comes in different types one is like a belt bag the only difference is that it is slimmer and can be covered by your shirt. So you wont have to go for your hand carry bag and dig into your belongings God knows whats in there... Another type is the one you wear it like a neck lace. You can also tuck it into your shirt but it would be awkward for the ladies... but there's no hard in trying right?
These products are available in the department stores wherein they carry Samsonite products. If you are in a tight budget you can purchase a wallet in Penshoppe for half the price.