This is true that to remain ahead in competition one has to put all the efforts in marketing and promoting of the products or services. Apart from local marketing, internet marketing has also the same and might be more important for the popularity of the business. So the best way is to work parallel on both techniques and just like mouth to mouth publicity use social media websites for a creative output.
Well patience is the foremost requirement in this business, you need to look for the commodity pattern that comes in orders frequently so that you can set your target accordingly. One most important thing is how well planned are the marketing strategies of your business to get it recognized and get preference among the competition.
Marketing a business is difficult only when you have no experience in the field, according to your situation as you have ample experience then only a little help from a marketing agency would help in successfully run your business.
As the designs are the only thing that you would be importing then a major percentage of profit share must be kept by you. Starting from a ratio 20 : 80 you must not settle it more than 30 : 70, as most of the efforts are taken from your side.