Besides your technical skills, you'll need to be able to
a. LEARN. You'll continually be learning new things on the job. You'll need to be able to learn new software and systems. You'll need to learn how other people do their jobs. You'll need to learn about new materials and processes, and not just in the abstract: you'll be out there and learn about the particulars of why a place does things and how they do them. You'll need to learn to read drawings and specification documents to understand what is important.
b. COMMUNICATE. This is particularly important when you deal with non-materials engineers. Other engineers think they know our topic, but most don't know anything or know just enough to be dangerous. So when you need to communicate something technical, assemble your facts in advance and speak/write with confidence and authority. If you have to deliver advice that contradicts another engineer, you should be able to state why your advice is better. Speaking succinctly with confidence and authority comes with practice and experience, and when you do so your customers will come to believe you.
Another part of this is knowing your audience. When talking to other materials engineers you should be able to use most or all your materials specific vocabulary. When talking to other engineers you should be able to give them the information they need without using a lot of materials jargon. When talking to non-technical people, that's another type of communication.
c. ANTICIPATE. You should be able to anticipate your customers' needs as you get to know them.
d. Getting back to technical skills, understanding materials properties, performance and processing is most important.
As a Production Engineer the primary focus is on developing future systems and maintaining existing systems. With either there is a significant amount of design of experiment, data collection and trouble shooting. With all of this a good understanding of mechanical systems as well as working knowledge of excel (Boeing loves Excel) is very important.