Like most financial advisers, I’ve spent (and still spend) a good share of my time building on the technical knowledge I need to do my job. The financial industry is always changing, and it’s important to stay on top of new theories, trends and tools.

But after 25 years of working with retirees and pre-retirees, I’ve learned that experience — and a lot of listening — can be every bit as valuable. It helps me to ask the right questions, keep an eye out for potential red flags, and to understand (as well as predict) certain emotions and behaviors.

Helping clients plan for a successful retirement means sharing the lessons I’ve learned during that time. Here are five lessons that stand out:

Don’t underestimate how much income you’ll need in retirement.

It’s amazing how many people who are in their 50s and 60s don’t maintain a budget or a good idea of how much they spend each month. I get it — it’s tough to list every expense each day to determine where your money is going. But it is possible to take a simpler, more top-down approach.

Start by looking at your earnings minus taxes each month. Then subtract whatever you’re saving in investment and/or savings accounts, or even in a shoebox under the bed. The end result is what you’re spending.

It’s easy to overlook costs that come directly out of your monthly paycheck right now, including health and life insurance or other bills on autopay. And many people don’t count the money they’re giving to their kids, grandkids, church or charities. Other expenses can just slip by, such as lunches with co-workers or a new pair of shoes. But you’ll likely have similar expenses in retirement — or maybe some new ones if you plan to travel or pursue a hobby. Building a reliable replacement “paycheck” is critical to retirement success, and the planning starts with knowing what you’re spending.

Consider dipping a toe into the retirement waters instead of diving in headfirst.

Most people I counsel are really looking forward to a relaxing retirement after decades of working. But it can be difficult to go from working 40 hours or more a week to suddenly having no schedule or daily regimen. Some folks have hobbies or they donate their time, and that makes for a less abrupt transition. But I’ve also known many retirees who instead went from full-time to part-time employment, and they were glad they moved slowly into retirement. Some stay in their current field, often working as contractors. Others pursue a new passion or something creative — a part-time job at a flower shop, for example.

Working part time has two benefits: It brings in a little income, which is never bad, and allows you to ease into a more laid-back lifestyle.

To accurately assess risk, change your perspective.

When talking about the potential for gains and losses in your portfolio, ask your financial professional to speak in terms of dollars and cents. When advisers explain investment risk, they tend to speak in percentages.

For example, they’ll say that in a market pullback your portfolio could lose 10%. And that might not sound so bad … until you translate it into lost dollars. If you have $1 million portfolio, that’s a $100,000 decline. And even if you can handle that kind of loss financially, you might not be up for it emotionally. Percentages just don’t seem to trigger the same kind of caution as dollars, so keep it in those terms if possible.

Avoid a piggy-bank mentality.

I’ve found that most people try to confine their spending to what’s in their paycheck while they’re working. Any money they have in retirement savings is typically tied up in accounts that have restrictions and penalties for early withdrawals, so they tend to maintain a hands-off approach.

Put a priority on protecting your money.

There’s an old sports quote that says, “Offense sells tickets; defense wins championships.” That’s a good way to think of your portfolio when you’re near or in retirement. Yes, it’s exhilarating to keep growing your money, and you want to build an income that can stand up to inflation. But it’s crucial that investors remember bear markets are a regular part of our investment history. In retirement, a bear market can be devastating. When you’re drawing income from your assets, it’s incredibly tough to come back from a major downturn. Even when the market rebounds, you aren’t necessarily in a position to take advantage because you aren’t contributing anymore.

So, it’s important to find ways to protect your money. Most financial professionals will discuss diversifying your assets, but make sure you really drill down in that regard. Get rid of redundancies and rebalance when necessary. Also, consider tactical management as a further safeguard; ask your adviser about monitoring market signals so you can move safely to the sidelines when things look grim and then get back in when the market improves.

Choosing the right investments is, of course, an important part of preparing for retirement. But proper planning is a huge factor in helping people achieve their desired retirement lifestyle after years of working and saving. It isn’t just about building a portfolio — it’s about securing a happy and comfortable future.

Kim Franke-Folstad contributed to this article.