jimdiverman
Contributor
I have found that retailers that really know their stock get you to take your measurements before they try to size you. They know where the actual sizes fall into the sizing charts. Even if you order online, you can generally speak with someone about sizing before you make the purchase. That gives you an extra measure of security if something doesn't fit, and lets the seller share some of the responsibility for selecting the size. Most reputable retailers, online or not, will stand behind their own recommendations.
If I'm going to wear it I have to try it on first to make sure it fits and feels comfortable. That not only goes for scuba gear but clothing as well. I would not buy a pair of shoes from a catalog assuming that just because they look good in the picture that they'll feel good on my feet. You may find out that suits off the rack will not fit you so you'll have to get a custom made suit. It will be alot less expensive to find that out trying suits on in an LDS versus sending them back and forth thru the mail. 