None of us can predict when a financial emergency will arise, but we can all bet on one thing: At some point, an unplanned bill will creep up at a very inconvenient time. If you don't have money in the bank to cover it, you'll risk racking up debt that you might really struggle to pay off.

Unfortunately, 28% of Americans have no emergency savings, according to a survey by Bankrate, which means they're putting their finances at risk in a very big way. If you're one of them, it's imperative to build some cash reserves -- before the next unanticipated bill hits.

Building your safety net

You can't establish an emergency fund overnight, especially if you're starting with no savings. For true protection, you'll want at least three months of essential living expenses in the bank -- things like housing, transportation, food, utilities, and healthcare. For better protection, you should aim for six months of essentials.

Banded stacks of 20-dollar bills

Image source: Getty Images.

How will you pull that off? One of your best bets is to set up a budget so you can see where your money actually goes month after month. From there, you can identify regular expenses to reduce. That could mean canceling your gym membership, downgrading to a lower-priced phone or cable plan, and cooking at home rather than dining out or ordering in. The latter, in fact, can translate into huge savings if you tend to buy a lot of prepared food.

You can also look at lowering essential expenses. For example, if you're spending $500 a month to own a car between vehicle payments, maintenance, and insurance but can get by using public transportation, it might pay to unload that automobile. Similarly, if moving to a smaller apartment for a year shaves $500 a month off your rent, that's a move worth making to buy the financial protection you need.

Either way, comb through your budget and figure out where you're able and willing to cut back. Then take the money you save and put it directly into the bank.

Another option: Get an extra job. That second gig doesn't have to be something that feels like work. You can take a hobby you enjoy, like writing, web design, crafting, or cooking, and turn it into an income stream. Or you can try doing your full-time job on the side.

For example, if you're a software engineer, you can take on small side projects for different clients and hammer them out on weekends. If you're going to moonlight in that manner, though, it pays to clear it with your main employer first. Some companies prohibit employees from doing similar work on the side, so don't put your main source of income at risk to make some extra cash.

Building emergency savings isn't easy, but if you don't make it your priority, you stand to suffer when unexpected expenses come your way. Rather than let that happen, slowly but surely build that pile of cash so it's there when you need it.