Although muggings and other violent crimes are rare on Bali, stealing is a problem, particularly in resort areas with lots of tourists. Budget travelers are more vulnerable to theft than affluent tourists who take planes, taxis, and rent cars. Since travelers carry their money and valuables on their persons, they are prime targets for thieves. Suspicion and wariness demand constant effort. Not agreeable states of mind, they do prevent thefts, which would be more unpleasant.
The best measure against theft is to travel without jewelry, a watch, or camera. Balinese are proud and consider temptation an affront. The less you travel with, the less there is to steal, and less resentment is aroused. See what happens to your bargaining position if you flash money or jewelry. Lock up valuables or keep them out of sight. Travelers also rip off other travelers, so exercise caution around Westerners too.
Never carry a lot of cash, perhaps only US$50 to see you through that day or week. Whether it's English pounds, U.S. dollars or Australian dollars, keep your money in small denomination traveler's cheques, cashable at banks, shops, and restaurants all over Bali. Even if you go to a moneychanger twice a week to cash traveler's cheques, it's better than losing all your cash.