Take a whole bottle of aspirin. You WILL catch a cold, and aspirin is prescription only for 1/5 standard western dose.
Take a dozen of those tiny travel packs of tissues, wet wipes and small bottles of hand sanitizer to deal with the bathroom situation. Carry a backpack everywhere. Take a door hook to hang it so you don't have to set it on the dirty floor. Cuff the pants before a squat toilet. You'll be glad you wore easily rinsable shoes.
Embrace your inner barefootness when you enter living spaces, better yet bring a pair of slippers in your backpack.
Dont drink tap water, drink bottled water, but make sure the seal hasn't been broken and filled with tap. Or drink weak beer and soft drinks. Restaurants that offer boxed fruit juices are enough for 2-3, split one with a friend.
Avoid foods on ice, iced drinks, and freshly washed produce. Choose fruit you peel yourself over cut fruit. Avoid vendor stalls that prepare food with tap water. In general, choose cooked over cold or raw veggies. Noodles and soup are usually a safe choice but meats that arent cooked as you watch are likely not kept at safely hot temperatures to avoid bacteria.
Taste any food you are offered before someone tells you what it is. You'll be amazed at the tastiness of things you would never eat if you first knew what it is. Like, lamb organ soup, that shit is delicious.
Take extra luggage for bringing back souvenirs. Also a couple of those nylon shopping bags that fold up the size of a wallet.