You have to be responsible for all steps of the manufacturing process and build into your contracts any potential issues that may arise (factories want to do it cheap, you want to do it right). Give payments in increments so you have financial leverage (30-40-30).
Where I’m going in China, I don’t go as a tourist. The industrial zone is not a pretty place. You can’t rent a car, even if you wanted to. There is no public transportation. Pick-ups and drop-offs are pre-arranged with factories. The good news is that the factories love when I visit or, for that matter, when any Westerner visits. There’s a certain hospitality that can be found doing business in China that doesn’t exist to such a great extent in the United States. They book the hotels for me, all meals are provided. They roll out the proverbial red carpet when I visit, which is nice.