What tips would you share with someone who is looking to breaking into product management?

As someone who moved from a CSM role into product management, I get asked this question frequently. While my answers are specific to my own experience, I've seen them work for others that have moved into product roles as well:

1. The most straightforward way to break into product management is to make an internal move. However, this does not mean you should take whatever job is open as a means to an end. If you come into a role with a clear objective to leverage that into a PM job, it won't be received well. 
2. Look for small but growing companies where you can get your hands dirty across a wide variety of functions. A great example of this is a support position. You'll be very close to the customer and develop a deep understanding of their needs and use cases. You might then start to more broadly analyze trends over time and share that with product, engineering or biz ops as a way to help them make roadmap decisions.
3. Similar to the example above, find ways to get involved with product that are adjacent to your current role. (Make sure your manager is aware and ok with you taking on the extra work first!) It might be providing a monthly trend report, doing an analysis of the most common customer issues or points of confusion, or identifying potential areas of usability improvements.
4. Make your aspiration to move into product known over time. You don't want to come in on day one of the job declaring that your ultimate goal is to be a PM, but as you start to discuss career development with your manager, make sure they know that is a medium-long term goal for you. A good manager will find ways to get you involved with product and set you up for success. It's also just important for others in the org to know about your interest. One way you might do this is to set up coffee dates with other PMs on the team to learn about how they got into Product Management.
5. If moving internally isn't an option within your desired time frame, all of the above tips may help you leverage your current role into an APM role elsewhere, especially if you have metrics to back you up (ie, I created a monthly trend report that helped to inform 20% of our usability backlog over time).

I typically suggest to try to pivot into product management by changing a few variables but not too many - so you have a few strengths to rely on.

When you start a new PM role, you are exposing yourself to potential changes on multiple dimensions (in order of likelihood):

• Function/ craft: This one is non negotiable
• Manager: You will be reporting to someone else with new expectations and unknown working styles
• Team: Potentially joining a new set of teammates
• Domain: You may need to learn a new domain (e.g. growth, conversion, platform)
• Company: Exposing yourself to a new way of working/ company culture
• Industry: You may have to learn a new industry

A transition into product management function/ craft is hard enough as it is - moreover you need to convince someone to give you a shot at it. The more senior you are, the higher the expectations will be. So especially if you are targeting a lateral move from a less-than-entry level starting point, I would advise you to leave as many other variables constant as possible. Typically the best route is to do a PM trial on your existing team. That way, you are a known quantity and have better access to the trial anf wil also have higher chances of success.

I have two tips for breaking into Product Management but I'm sure there are many more. 

The first is to work with Product Management in your current role and/or talk to current Product Managers. Product Management can be seen as a very appealing job but many don't understand the day to day and trade offs of the role. By working with or informationally interviewing folks who are currently doing the job, you'll get more information on wether the job is actually for you and what appeals to you about it. 

The second is to ask your manager if you can work with Product or use Product principles in building something new or improving an existing thing as a special project. This could be an internal process, application, or something else. The idea is to apply product thinking and process to something in your current job to see if you like the way of doing work and the type of work.

Both of these suggestions will help you to both understand if Product is a career for you but also will prepare you to interview for the role.

I start working as a product manager from one unexpected opportunity from a career of 35 years of project management.

The role of a product manager is one of those less well-defined I have ever encountered. It can mean very different kinds of jobs in different companies. 

I would first advise reading about the experience of actual product managers in various companies via their blogs or some articles. and I would then consider if this is what I want to do.

I would try to reinforce some of the skills you will need:

• Be data-driven: You need to sustain all your decision as much as possible with data 
• But have gut feeling: You also need intuition, and as soon as you have a strong intuition, launch experiments to confirm or contradict it.
• No need to be too technical: there are people to be technical. Be technical enough to understand what is explained to you.
• be passionate: be passionate about the product, and be passionate about the users. You will be their ambassador. 
• Sharpen your writing skills: You will write a lot, much more than you imagine, so train to write clearly to be understood.

Speak with product managers whenever you can meet one and interview them as you would interview a user when you will be one of them.

Try to find a mentor (someone with a product career) and have regular sessions with him to help you get into the flow of product management.