Since product marketing is different at every company, what are some skills (hard and/or soft) that every PMM should have to ensure they’re as versatile as possible?

My former manager, Christy Roach, taught me the importance of the following skills, which I've applied to my PMM career to date. (Thanks, Christy!) So copying and pasting one of her previous Sharebird answers around this below:
Soft skills:

• Cross-functional excellence: As a PMM, you have the opportunity to lead without being a manager of people. A strong product marketer is someone who takes others along with them, rather than telling people exactly what they want them to do. They’re able to create strong relationships across the company, with product managers, engineers, designers, marketers, support folks, and more. They’re natural connectors who know who to go to in an organization to get things done and can influence cross-functional stakeholders to support and prioritize projects.
• Executive presence and clear communication: As you get more senior, you'll spend more and more time presenting plans, public speaking, and communicating with executives in the company. The stronger you are at presenting and public speaking, the easier this will be for you. Executive presence also means knowing how best to leverage an executive’s skills to get feedback that will help your project, manage their expectations, and ensure they feel like they’re in the loop about work that matters to them.
• A pitch in, get-it-done attitude: Being a PMM can be unglamorous at times. Sure, you get to run the big launches, but what people don’t see are the hours you spend writing support macros to ensure the team has what they need to answer incoming tickets, the amount of times a day you have to field seemingly random requests that don’t always fall neatly into your scope of work, and how often you get looped into last-minute, urgent projects that you didn’t plan for. PMMs that can approach this type of work ready to pitch in and help are often those that are seen as the most dependable and trustworthy, which helps them create strong relationships across the company. In my career, I've always made sure I'm never above doing the grunt work that's needed to get something across the finish line. While I don’t do it every day, I’m happy to roll up my sleeves to take a screenshot for a help article or write a macro if it means the team will be more successful and I reward members of my team that have the same attitude.

Hard skills:

• Market, competitor, and product expertise: PMMs should know their product inside and out, be an expert on its features, capabilities, and limitations, and be able to help partner teams figure out solutions to customer problems. This takes work, and it shouldn’t be overlooked. On top of that, you should know your competitors' products almost as well as you know your own. What does the competitor’s product have that yours does not? Where do you lose? Where do you win? How do they position themselves? These are all questions you should have an answer to. Last, you should know your market. What are the trends in the market in which you operate? What are the factors that influence decision making for your buyers? What’s coming down the line in terms of regulations or industry shifts that your company might want to get in front of? The better equipped you are to answer these questions, the more strategic value you'll bring to your company.
• Positioning, messaging, and storytelling: Messaging and positioning isn’t a soft skill - this is something you hone and work at. This skill is all about being able to create tight, clear, compelling messaging frameworks that identify the target customer, nail their pain point and the benefits your solution provides, and clearly explain how you're different than what else is on the market today. A leader I used to work under said “The person who most accurately identifies the problem earns the right to solve it”, and I think that’s a really clear articulation of how specific and focused you should be in your messaging. You always know when a messaging framework is ready for prime time when you would defend every single line of copy, are able to explain why each line is necessary, and can show how each phrase ties back to the feature or product itself.
• Know your customer: There are two parts to this. The first is knowing your personas. Specifically, you should be an expert in who buys your software, what their titles are, where they sit in an organization, what matters most to them, and how to market to them. The second is connecting that customer persona with actual customers who use your product. If you’re not talking to customers throughout your day-to-day, how can you represent the voice of the customer to the product team? I have OKRs for my team to have a certain number of interactions with customers each quarter to make sure that customer empathy doesn’t get lost in the shuffle. The key is getting these customer insights and then doing something with them to make sure that those insights are driving your roadmap and activities.
• Go-to-market planning and execution: PMMs are responsible for creating unique, impactful, cross-channel GTM plans that will help your product or feature hit it’s launch goals and drive sustained adoption and revenue. Product marketers should understand which channels drive success and identify the metrics they want to move so they consistently hit their goals. Another part of this is studying how other companies run their launches and taking inspiration from that for your own launches to up-level your approach.
• Process management: It’s often said that PMMs should act as the quarterbacks to a launch. A big part of this is ensuring there’s a process in place within the marketing team and with partner teams in order to make sure that everyone has the information they need and clarity on what’s expected of them to make the launch a success. If there isn’t a process in place, it’s up to the PMM to create and drive new processes to fix problems. It’s also up to PMMs to point out when a process is no longer working for your team.
• Making data-driven decisions: The need for data and analytical skills continues to grow in the product marketing space. I personally wouldn’t call myself a “numbers person”, and I don’t think you need to have the data skills of an analyst to do the job. That said, I do think you need to understand your company's baseline metrics, be able to pinpoint the data that would help the team make a decision, and back up your plans and initiatives with data that supports your proposal in order to succeed in your role and provide value to your organization.

Thinking back to the best PMMs I’ve worked with over the years – here are some things that make a stellar PMM:

• Super organized with project management experience

• Scrappy and able to try new things with a limited budget

• Great collaborators

• Able to lead and influence without “authority”

• Curious and shown that they have learned skills outside of their core role

• Nail the job specific tasks: positioning, messaging, content development, go-to market planning