Many people believe that the only way they can earn miles is if they are constantly in the air, traveling for business. While it's true that flying is one way to earn miles, it's certainly not the only way. After all, there's only so much flying one person can do.

Those of us who spend our lives earning miles and redeeming them to travel know that you must have more than one method to earn miles if you want to actually use them. Taking advantage of alliances, earning for frequent purchases, and sign-up bonuses are only some of the ways to earn. Here are a few ways I earn miles outside of flying.

1. Use airline dining programs.

Some travel rewards credit cards give you miles or points back for every dollar spent at a restaurant. But did you know that some airlines including Delta, United, Southwest, and American have dining programs that allow you to earn more miles for each dollar spent when you dine? 

Simply sign up and register your credit or debit card. Then you can start earning points at one of their participating restaurants, bars, or clubs. You can earn plenty of points while taking clients out to lunch or dinner.

2. Shop on airline shopping portals.

Since the internet has made shopping more convenient, many people do most of their shopping online. Next time you want to shop online, instead of going directly to the retailer's website, go through your airline's shopping portal and get miles on every dollar you spend.

Most airlines always have a special deal going on where you can get extra miles back per dollar spent on items that you would've bought anyway. Some airlines that have shopping portals are American, Delta, Alaska, United, and Southwest.

3. Use credit cards that fit your needs.

Some business credit cards let you earn 3 points per $1 spent on expenses such as internet and cable. Others let you earn 5 points per $1 spent on office supplies. If you know that you have both those expenses, then don't use only one credit card to earn your points.

To earn the maximum amount of points, pay with the card that earns most with your common purchases. Aim for travel credit cards that are partners with your favorite airline so that you're earning miles you can actually benefit from.

4. Autopay your business expenses.

As a business owner, you understand that there's always an expense you have to pay for. For instance, you likely have rent, paychecks, and a recurring web security expense for your website. Once you know what bills you can get the maximum amount of points from, put those on autopay.

Even if there's not a category bonus, you're often still earning at least 1 point per $1 spent.

5. Book hotels.

Some hotels have partnerships where you can book directly from the airline's site and earn miles. There are usually a wide variety of accommodations you can choose from, including stays at Marriott, IHG, and Hyatt properties.

For instance, American Airlines lets you both earn miles for hotel stays and convert your hotel points for miles to redeem for travel. To do this, simply log in to the hotel's website, select miles as your preferred currency, and enter your unique rewards/loyalty number. 

6. Use rental cars.

If you have a preferred rental car company that you like to book with, see if your preferred airline is partnered with them. For instance, you can earn as much as 1,250 miles with American Airlines each time you book with Avis or Budget, depending on your membership status.

One thing to remember is that you have to look into each rental car company's partnership with the airline. With some you can earn miles per rental, while others are per day. So, if you're trying to earn the maximum amount of miles for your business and you're preferred rental car company doesn't offer the best deal, consider renting with another company. You may even find a new favorite.

7. Transfer points.

As mentioned before, you can earn points for putting your bills on autopay. However, you'll need to transfer those over to your credit card's partner so that your points are converted to usable miles. Some airlines are partnered with hotels, and you can earn miles for booking through that hotel's loyalty program. Then, you can transfer your hotel points over to the airline and convert them into miles.

Once you know all the different ways you can earn airline miles for your business, you can start racking up on them in no time. The key is to figure out how to make these methods work for you. Before you know it, you'll have more miles than you can use.