What's the best way for a small manufacturing company to obtain corporate clients?
Usually I would recommend staying away from consignment until you are much bigger because your cash flow cannot handle being the banker for other companies.
As for what stores look for, a product that sells itself--very simple if you can get the ammo to sell--they will be impressed, so plan some sort of event in their area if they purchase a minimum order quantity. That way they order a good amount from you, you get to run an event to promote your products, they get to have new customers and their old customer invited to a good time.
All the Best,