Since you are heading to Bali, make sure that you read up on the immigration and emigration laws in Indonesia to prepare for your trip. You should have with you, your visa, passports, photographs for identification, health and insurance certificates, numbers, any immediate or emergency contact numbers for your embassy both in Bali and back home. If you are bringing money make sure that the purse you are putting all your cards and cash in is a secure one that can be locked and kept on your person all the time. Frequent flyer miles and other such details required by the airport should be kept somewhere that you can reach for them without worry.