Perhaps the greatest concern women have while shopping for clothing online is whether the item will fit. Though you may never truly know until you put the item on, the guesswork can be significantly decreased with a little effort on your part. First, take the time to measure your chest, waist, and hips (the tape measure should go around the widest part of your bust and hips, and the smallest part of your waist). About.com has a helpful instructional guide about measuring yourself, including some tips on figuring out your bra size. Keep your measurements on hand while shopping, and consult them -- along with the store's own sizing charts -- for every item you're planning on buying. Don't rely on what size you think you may be, because sizes are ultimately arbitrary when proportions vary from store to store. You may be a medium in general, but for a particular retailer, you could skew a few sizes higher or lower. This is especially a concern with designer apparel or European brands, which almost always run small.
What this ultimately means is that you must leave your hang-ups about sizing at the door, and that these measurements will be a reality check when deciding if the garment really is worth the price. If the item is an incredible deal, but doesn't quite fit, tailoring might be an option. Seams and hems can be taken in or let out, leaving you with a perfect-fitting garment. Just remember that long hems and straight side seams are the easiest to get fixed; darts, shoulder seams, etc. are more complicated and, ergo, more expensive. Also, letting the hems or seams out on an item is doable but dicey since you can't tell if you have enough material until you actually look at the garment in person.
The fabrication will further instruct your judgment about an item's fit. For example, if a shirt falls a smidge short of clearing your chest, but it's made of a stretchy jersey knit, the shirt will likely still work since it has plenty of give. The same can't be said of a cotton button down which should fit your chest measurements exactly (otherwise you'll get gaping between buttons). The material will also tell you what the item might look like in person. Even if fine materials like cashmere, silk, or merino wool look different than they do online, they are high-quality and will likely look rich in person. Synthetic blends can be risky; if you can, try to zoom in on the fabric as much as you can to see the texture. It's as close as you'll get to a tactile evaluation of its quality. You can also take the added steps of optimizing the color quality settings on your computer so the color isn't distorted.
The final way to take some serious guesswork out of online shopping is to know your body and what styles flatter it. For example, if you don't already know what trouser silhouettes look good on you, head to a brick-and-mortar store and try on loads of styles until you can recognize what shapes work best for you. Check out the names -- straight leg, boot cut, flared, etc. -- but also lay the clothing flat and note its proportions; if you can recognize what silhouette looks good on you in this way, identifying the same online will be a cinch. You can conduct the same "analysis" of your favorite-fitting garments in your own closet as well. Soon you'll be able to instantly recognize whether an item's construction can work for your figure, making navigating sales much easier.
Finally, we've found that store's are always eager to ease your anxiety about buying online -- it's in their best interest -- so you can always email customer service or speak to a rep via IM to ask more specific questions about an item's fit. We've also encountered an ingenious online tool called Size Me Up which compiles information about your favorite-fitting items you currently own, compares it to its existing data about other retailers, and then tells you what size you would likely be for various stores and brands. The tool is still in beta, but you can input your information and you will be notified when it "goes live".
The bottom line is this: if it won't fit, don't buy it! We know it can be upsetting to pass up a beautiful steal, but think of it this way: you'll save the money for that next adorable frock that comes your way.
-- Lindsay Sakraida