If you've spent years occasionally selling your unwanted trinkets or random garage sale finds on online auction sites, you may have discovered that the popularity of these sales sites has boomed recently, with a number of individuals waving goodbye to the rat race and becoming the proprietors of their own internet-based sales businesses. While this can be a lucrative opportunity for the right person, there are some rookie errors that can limit your success.

Read on to learn more about some of the shipping and other logistical factors you'll want to take into account when expanding your online sales or merchandising business.

Create shipping 'profiles' for common items

If most of the items you're selling are the same approximate size, shape, and weight, you won't need to spend much time calculating shipping costs and may even be able to simply set a flat rate for your entire product inventory. However, when you're regularly shipping wildly different items, determining the cheapest and safest shipping method (while ensuring your sale price remains high enough to turn a profit) for each item can be time-consuming and inefficient. 

Instead, you may want to create shipping "profiles" for common items. By doing a bit of preliminary research into the safest and least expensive custom shipping options for each size and shape of item, or even enlisting a shipping company to do these calculations for you, you'll be able to instantly compute the shipping cost for just about every item you carry. 

Taking the few minutes needed to set up new items in your system can save you hours going forward, giving you the flexibility to spend this time seeking out new profitable items or just enjoying time spent with your family. 

Track your inventory carefully

With a wide variety of spreadsheet-creating software available—both for purchase and on the open web—there's little excuse not to have an electronic database of your current inventory. Creating an inventory, even a simple one, before you begin selling in earnest is a key component of a successful online sales business; waiting until after you've added more product can put you behind the 8-ball and leave you feeling disorganized. 

When creating an inventory spreadsheet, you may want to spend some time brushing up on your spreadsheet skills. In addition to simplifying the basic functions like addition, multiplication, and some simple algebra, most types of spreadsheet software can allow you to sort and filter by a nearly endless number of categories—drilling down to see your most (and least) profitable items, your most popular items, the number of sales you made during the previous month, and nearly anything else you can think of. 

Once you've become comfortable with your inventory spreadsheet, you may be able to go a bit more advanced. For example, you may be able to connect your email account or merchant account with your spreadsheet to automatically import sales data each time a sale is made. Automating as many of these processes as you can (albeit with periodic quality checks) can be a great way to free up your time for more entrepreneurial pursuits. 

Stay on top of trends

Nothing is more disappointing in the online sales business than finding yourself stuck with product you're unable to move—even at below-market prices. And because many of the most profitable products are made profitable through their scarcity and "fad" nature (especially during the holiday season), obsolescence can be an inherent risk of this business model. 

To lower your risk of becoming stuck with surplus inventory that's no longer selling at peak price, you'll want to keep a careful eye on trends and avoid becoming greedy—setting your price too high during times of peak demand can send frenzied shoppers to other vendors, and you may want to begin lowering your price or adding other promotions as soon as you notice a dip in sales volume of a trendy item.