In this segment from Motley Fool Answers, Alison Southwick and Robert Brokamp break down a proper investing and retirement strategy by decade. Here, they turn their attention to our 30s -- we're buying homes, getting married, and having kids. Financially speaking, the team says there are a few things you should be making a real priority at this stage in life: establishing your career, matching your financial needs to your family needs, and potentially buying a house. They also share one of the biggest financial mistakes people make in their 30s.

A full transcript follows the video.

This podcast was recorded on April 18, 2017.

Alison Southwick: Your 30s are an exciting time. You're hitting all the major milestones. Marriage, home ownership, kids, and a career. You're making a lot of decisions and because of those aforementioned kids, probably on very little sleep.

Robert Brokamp: So true.

Southwick: So what should be your priorities in your 30s?

Brokamp: Well, you touched on it there. Number one is really your career, and that is being very strategic about your career. Your job is going to determine so much about your finances. Your income. Your benefits. Your retirement. The quality of your 401(k) and whether you have a pension will be a big factor in your retirement savings. And even, of course, your happiness. So you want to make sure you have a job that you enjoy, but I think it's very important to be strategic about it and to continually come up with ways to make yourself more valuable to your employer, to your colleagues, and to your customers.

Number two is to arrange your finances for a family. That has several aspects. First of all, it's a slightly bigger emergency fund. It's time to get life insurance. You probably haven't thought about that, but once you have kids you really need to get life insurance. It's also time to finally get an estate plan. The majority of people in America don't. According to a Gallup poll last year, only 44% of Americans have a will. But once you have kids, you need to set up your finances in a way to take care of them in case something happens to you.

And then the third priority in your 30s is to maybe buy a house.

Southwick: Maybe?

Brokamp: We've talked before about how it's maybe not the best thing in the world, but most people do, especially once they have a family. Just keep in mind that you want to be buying a house you're going to be happy with for at least six years and ideally a decade.

Southwick: And how much should you have saved for retirement in your 30s?

Brokamp: Once you're at around 30, you want to be aiming for about one-half of your household income. By the time you're in your mid-30s, you want to have about one to two times your household income stashed away in your 401(k)s and your IRAs.

You can also add other things to that. Maybe employee stock if you receive it. Maybe home equity if you plan to downsize when you retire. But for the most part you're really just looking at how much money you've saved in your retirement accounts.

Southwick: And what's the biggest mistake to avoid in your 30s?

Brokamp: I would say buying too much car and replacing it too soon. Remember when we're all in our 20s, we're driving a piece of junk. And finally once we're in our 30s, we have a little bit of money. We decide to buy a car. Maybe we buy too much of a car, or too nice of a car, and we sell it too soon.

According to IHS Automotive, the average new car purchased [is kept] for about 6.6 years, which is actually longer than it used to be. So people are getting this message, but the average life span of a car that's on the road, now, is almost 12 years. In other words, they could keep that car longer, but they choose not to. But you think of even just putting off a new car purchase a year what the average monthly payment is now -- between $400 and $500 --and that's several thousand dollars more you can save just by keeping that car for another year.