The days of spending your working life in a single job or, in many cases, even a single profession has passed.

Markets are rapidly changing, and sometimes people make big career changes because they have to. If you work in parts of manufacturing, or in many retail jobs, automation may force you into a new profession whether you want to make a change or not.

In other cases, people make a major career change because they want to explore a new area. Perhaps it's about following a dream, or maybe it's a case of trying to make more money (and sometimes it can be a bit of both).

Whatever the reason, it's possible to switch careers. It does take planning, persistence, and sometimes a willingness to close your eyes and leap, but it can happen. Below are three pieces of advice from a group of Motley Fool writers to help you make the transition.

A man with a briefcase stands at a crossroads.

Making a career change may be easier than you think. Image source: Getty Images. 

Swallow your pride

Maurie Backman: If you're about to embark on a career change, one of the most important things you can do is swallow your pride and accept that you may need to start at the bottom, regardless of the success you may have achieved at your former job.

While it's true that certain universal skills, like time management and a knack for public speaking, can easily translate from one job to the next, if you're moving over to a whole new career, you may lack a degree of knowledge and expertise that only comes with time spent on the job.

Think about your last career, in fact. Chances are, you knew less about your industry five years ago than you do today. The same likely holds true for your new career, so keep your expectations in check, and don't get frustrated if you wind up in an entry-level position, even if you've got years of experience under your belt.

Just as you probably worked your way up at your last job, so too will you eventually get the opportunity to prove yourself in whatever new role you wind up accepting. And if you're willing to put in the time and effort, you might find yourself up for a promotion before you know it.

Do a lot of research 

Selena Maranjian: Before you try to jump into a new career, do a lot of research first. You might want to switch into a certain different career because you have noticed that it tends to pay very well and jobs are likely to be plentiful. Those are great reasons to consider switching, but they're not enough. 

Do a deep dive into the career and learn a lot about it. Read as much as you can about it, of course, but find people in the field to talk to also. Ask them detailed questions about the job. For example, what are typical days like? How do they fill their hours: On the phone? in meetings? Trying to sell things? Giving presentations? What skills are most important? What training, courses, degrees, or certifications are useful or necessary? What do they find rewarding and frustrating about the job? Why are some people unsuccessful at the job? Why would or wouldn't they choose that career again, if they had the choice?

Questions like that might help you realize that the job is or isn't a great fit for you. You may not have appreciated, for example, how much telephone work there is, and you may hate using the phone. You may not enjoy or be good at writing or math, but the job might entail more writing or math than you expected.

The more you know about the possible new career, the better you can assess how well it matches your skills and interests. Ideally, the new career will involve doing the kind of work that makes you happy and energizes you.

State your case

Daniel B. Kline: After beginning my career as a journalist I took a four-year foray in my family's ladder and scaffolding business. When it was time to leave that job I was pretty sure I didn't want to go back to media because that job market was not in a great place, but I also knew I wasn't going to stay in the construction or even the business to business sales space.

Instead, I began applying for any job that seemed interesting that I believed I could do. Even if I was missing qualifications or experience asked for in the ad, I used my cover letters to carefully explain why I could handle the position and how my experience related.

In many cases, I'm sure this led to my resume being thrown away. In a few though I received interviews and that's when I took stating my case even a step further.

I went into each interview not just ready to sell my self, but with a plan as to how I would do the job. Acknowledging that all plans changed, I not only laid out how I would advance my own knowledge, but also what I would do in my first 10 days.

It was a bold effort to stand out that was needed because my experience was almost certainly not like the other candidates being interviewed. I was making my case and explaining why different was not only OK, it was better.

Those efforts worked and I spent two years running a giant toy store before making another career change into non-profit public relations, then running a group of rock band summer camps. Eventually I found my way back to journalism, but had I not sold myself, my journey here would have been a lot less interesting.