Read the Reviews
Reviews posted by other consumers, particularly those that offer feedback on the particular clothing items you're considering, can provide valuable insight. You'll especially want to know whether others believe the garment is true to size because children's clothing sizes aren't always uniform. For example, a size 4 at one retailer may be wider, slimmer, shorter or longer than a size 4 at another.
Remember, however, that a user review posted on a retail site is just one person's opinion. For the best results, you'll want to look for multiple reviews written about the same item. For the most part, you can disregard the best and the worst reviews; the truth is often in the middle. For example, if one reviewer assigned a stellar five-star value to a boy's wool sweater and one reviewer gave it a poor one-star rating but 20 reviewers found it to be of 4-star quality, trusting the majority of the reviewers should yield reliable results. You also should check out Web sites that offer professional reviews of products, as well as those that cull reviews from many different places.