Some customs in Bali are quite different from the US, so try to read up a bit on local customs before you go if you want to blend in more!
Pointing at someone else using a finger is considered rude—use your whole hand to gesture instead of pointing.
Be aware of daily offerings placed on streets and beaches. These are small trays offered to gods in the morning. Be careful not to step on them or walk over them
Balinese people tend to avoid conflict—if you have a problem with a hotel or some other service, try to be calm and humble when attempting to resolve the problem. Showing anger, shouting or being visibly upset will not help you!
Smile often! Balinese are warm and open people—being friendly by smiling when you interact with locals will be appreciated by all and will cover for smaller cultural errors.