They will do your laundry at a reasonable price, so once again, another reason why not taking too many clothes with you. T-shirts are for sale all over the island. European, Chinese, Japanese, Indonesian, etc. But make sure that you are eating fresh food. The best advise I can give, is to go to restaurants that have many visitors.
Many tourists get ill after eating uncooked food.
Although I am not a fan of this junk food, the potential risk is remarkably lower than at small restaurants. This doesn't mean you cannot eat Indonesian food. When I came back to Belgium, I missed I missed the AQUA water a lot. Just buy a couple of these bottles so you can drink fresh water all the time. And in the smaller restaurants, be sure the bottles of water are still bottled.