After doing some electronic goods trading with China, I can say that the main issue is to make sure that what you receive is what you paid for.
Specs have a way of changing without you being informed. Consistency of quality is pretty random as well.
So you have to make sure you inspect the goods before you take them.
Also, almost all manufacturers and distributors will make you pay before at the latest at the time the goods are departing. No 60 day or 120 days credit here.
You get the cash, you get the goods, most of the time.
If you're a larger trading company, you can have the support needed to inspect and ensure that the goods are up-to-spec.
Then there is Alibaba. Small quantities for direct sellers are usually OK (although quality varies greatly). At least you have buyer protection and the sellers are very careful about maintaining their reputation so they are usually prompt and efficient.
Finding a factory for something you want to manufacture (or for large orders) can be fraught with issues, the first of which is that I'm yet to find a factory that can honestly tell me they can't do something; whatever you ask, you'll get a "yes". If you have no production experience, you're in for a ride.