Everybody wishes there was an easy way to bring in a little more money each month. But perhaps we have unwittingly been jeopardizing our own bank accounts this entire time.

A financial advisor who has managed over $100 million over the years has now shared the biggest money mistakes people make - and how you can avoid them to set yourself up for success. 

Terry Tully, 43, from New Orleans, Louisiana, has spent nearly two decades helping people prepare for retirement and grow their bank accounts.

Along the way, he noticed that many people unknowingly miss out on earning thousands of dollars because of a few simple - and preventable - errors.

Whether it was by not taking advantage of employer benefits, not knowing what types of stocks to invest in or paying a fee they should have avoided, he has seen firsthand how money faux pas can get in the way of long-term growth.

During a recent chat with the Daily Mail, Tully explained that he has been 'hooked' on watching the stock market ever since he was a kid.

'My grandfather bought me my first share of stock (AT&T) when I was a kid, and that completely changed my world,' he explained.

'I'd watch CNBC even though I had no idea what they were talking about most of the time. I just knew it was something I wanted to be involved in for the rest of my life.' 

After earning his degree in finance in 2008, he started working as a financial advisor and eventually went on to launch his own company called Ebb.

It's dedicated to showing people exactly where their retirement account stands and what they can do to improve it.

'Most people have no idea what's going on inside their retirement accounts,' he explained. 

'[Between] hidden fees and confusing investments, [people have] no clue what they actually own or what it's costing them.

'And the worst part? That's exactly how the system is designed. That didn't sit well with me. People deserve transparency, and right now they're not getting it.'

Tully insisted that it's never too late to start growing your bank account and investing in your future. 

Avoid making these common money mistakes if you really want to succeed.

The expert explained that the first error people often make when it comes to saving and investing is believing that they're too old to start.

'It's [never] too late,' he stressed. 'I've worked with plenty of people in their 40s and 50s starting from zero.

'Starting late isn't the problem. Staying on the sidelines is. The biggest risk isn't doing something wrong… it's doing nothing.'

Tully added that investing later in life just means the 'margin for error' is smaller, which in turn means that you need to be 'more disciplined and save more aggressively.'

Tully noted that the hardest part for most people when it comes to saving and investing is taking the initial plunge.

He explained that most people don't know where to start and feel overwhelmed by all the choices and information that's out there. 

But if you have absolutely no idea where to begin, he suggested starting with your 401(k) account.

And if you're not taking advantage of an employer match, you're making a big mistake.

At most companies, you can opt to automatically add a certain percentage of your paycheck into your 401(k) and your employer will match that amount, which Tully explained is basically 'free money.'

'The first thing I tell people is to make sure they are contributing enough to their 401k to get the full employer match,' Tully said. 

'Even with all the hidden fees and sometimes bad investment options, this is still free money that you are leaving on the table.'

Tully explained that on top of contributing to your 401(k), you should be investing any extra funds that you have.

If you're unsure what stock or fund to invest in, he suggested you start with 'low-cost index funds' because they're 'cheaper than traditional mutual funds' and are 'widely available and easy to understand.'

'They take a lot of the guesswork out of investing,' he explained. 'Most people don't need a complicated strategy… they need a simple plan they actually stick to.'

Tully said a 'simple rule of thumb' everyone should live by if they want to get ahead financially is to invest '15 to 20 percent' of their income.

But he added that the key is consistency and stressed the importance of investing every month - even if it's just a few dollars. 

Tully explained: 'I know [investing 15 to 20 percent of your income] is not always an option, so the most important part is to just start with whatever you can afford.

'Time is your best friend when it comes to investing. Let compound interest do its thing, and you'll be amazed at the results. Even if it's $50, just start.'

According to Tully, another huge mistake that people make when it comes to their finances is 'ignoring or overlooking fees.'

'[People often] think, "One percent isn't a big deal." It is,' he said.

'Over time, that one percent can quietly cost you hundreds of thousands of dollars. Pay attention to fees. That's the silent killer.'

He suggested 'taking a hard look' at every fee you're paying and if you're working with a financial advisor, make sure they are upfront about exactly how much they are taking out of your investments. 

'Compare what you're paying versus what you're actually getting in return and ask for lower-cost options,' he stressed. 

'Fees are one of the few things in investing that are guaranteed. Returns are not.'

Another costly error that people make when it comes to investing, according to Tully, is panicking if the stock market goes through a rough period.

'When the market drops (which it will) don't panic,' he said. 'A ten to 20 percent drop feels scary in the moment, but it's part of the process. 

'That's when the market is essentially 'on sale.' The people who win are the ones who keep going when everyone else hesitates.'

Tully explained that another problem people often endure is that they increase their spending as their savings build.

He explained that it's vital to keep the same lifestyle even as your net worth grows if you want to get even richer down the line.

'The biggest problem I've seen over my career isn't bad investments. It's lifestyle creep,' he said. 

'As people made more money, their expenses followed right behind it. Bigger house. Nicer car. More vacations. Not because they needed it, but because they could. 

'I watched people overextend themselves chasing things they didn't actually need. And if they truly understood what those decisions were costing them long term, they'd think twice. 

'A lot of people aren't buying things for themselves. They're buying them to prove something to everyone else. And for what?'

In the end, he reminded people that growing your finances takes time and effort and it doesn't happen overnight. 

'Retirement isn't a sprint. It's a slow, steady build,' he concluded.