One is the selected manufacturer should have rich experience in American style cabinet production. Experience is always a valuable fortune for anyone that help avoiding the same mistake.
Two is that this manufacturer must be a well organized one. This point become even more important than experience, under some circumstance.
The Third, I find it's often important to observe/examine the character of its owner, or say its business culture. There's a story: Once I took one customer to a factory. Good facility, management looks good at least seemingly, capacity is big. Then we sit down with the owner. My customer grabbed a sample door from a corner accidentally. She pointed at the glaze line on it and said, "see, this line is not straight, we don't expect it in future". The owner seems indifferent and said " Oh it happens, so what the fuss". So that's it. This manufacturer just don't care much about the products they built. Moreover, one of our task is to get good price but we never should compromise on quality issue.
One good way is to use a Paul Cabinet Sourcing cabinet manufacturer. All of the cabinet factory Paul Cabinet Sourcing worked with are carefully evaluated, and selected. These cabinet factory can provide reasonable price, as well as consistent quality kitchen cabinet and bathroom cabinet.