Modern Marketing Strategies fit for a Manufacturing Company

Being in a manufacturing industry for almost 20 years, our company has maintained a strong good working relationship with our customers, whether locally and abroad. We have protected and maintained our branding and our old customers still being patronized. But due to a lot of new competitors of this modern age, we noticed that most of our customers now, whether old and new, they became slowly turning their attention to new faces, i.e. have modern ways to market their product ( though we see we offer the same product). I can say that our marketing strategy is like the old style marketing ( I think weak, only focused on existing customers) , I.e. we got a sales and marketing department who talks / negotiates directly to another customer. Some kind of B2B. Right now, we have one (1) Sales and Marketing Manager who handles all our negotiations with our existing customers, but it seems we don't see any potential new customers. The company is foreseeing to have future expansions, but this cant be possible if the company don't have enough sources. In this modern age, being up to date with the new market tools and strategies is a big factor to penetrate the new market. I would like to seek those marketing people today, what can you suggest to an old manufacturing company to gain new customers and opportunities? Thanks for the help! Note: I'm just a young professional which is not a sales person. I just want to know from a point of view of marketing person which factors to be considered, because I want to help our Business Enhancement Team and to gain more understanding about this process.