Javanese people don’t blow their noses very. If a Javanese person really needs to use a tissue, he/she will throw it away after one use. Putting a dirty tissue into one’s pocket is considered disgusting.
When you ride on the back of someone’s motorbike, do not hold on to them, unless it’s your partner, a close relative, or a close friend of the same gender, who is driving. If you feel you need to hold on, use the handle behind you.
Javanese people tend to avoid flashing their money around. If paying for something they quickly have money ready, and don’t count it all out in front of everyone.