MURO suffered an almost instantaneous set-back after we had our successful Kickstarter; we lost our supplier! (don't worry it was mutual)
Finding a supplier for any original design manufacturing (ODM) is always going to be a challenge, especially if it's your first project. After a few attempts we originally settled on a large established factory in China, they were confident they could deliver, and the original samples needed work but were close to what we were after.
However, when the next round of samples arrived ahead of an order, the quality had gone down hill. But worse than that, responses were going unanswered and proposed solutions to our concerns were slow coming.
Once it became clear it was not going to work we went back to the drawing board and started the process again. This process is a lot like dating: it takes up a lot of time, countless messages and there are no guarantees as both sides get a sense of one-another.
The aim is to find someone who buys into what you are doing, and is willing to work with you. We're now in a happy relationship, but here are somethings we noticed along the way:
1) Good communication.
Timely and fluent English are not always good. Do your questions get answered? Are answers considered and problem solving? Beware of "yes" people, they will promise much more than they deliver.
2) MOQ and factory size.
Minimum order quantity and the size of factory are very important; you need to make sure your predicted volume and a suppliers expected volume are in the same ball-park, if they're not then it's game over! More subtle is the size of the factory, and its a bit of a 'goldilocks game', too small and they won't be able to do what you need, too big and they won't give you the attention you need to get production started.
3) Manufacture their own brand.
If a supplier manufactures their own brand of products in a similar market it's a great sign as they will know what customers expect. They may also be aware of regulatory restriction you need to comply with.