Bridal sessions. If you are from the northern US or either of the coasts, you may not even know what this is. It's a southern thing, y'all. Bridal sessions are a portrait session taken just of the bride (usually before the wedding) so that you have something you can print and display at your reception. There's rarely time to get more than a handful of photos of just the bride on the wedding day. AND the most important reason....to test out your wedding day look.
I shoot a lot of bridals and I think they are so important because it gives you an opportunity to see what you look like in your dress with your hair and makeup done while holding your bouquet. I'd say about 75% of brides actually change something up pretty significantly before the wedding. Here are a few examples.
Hannah wore an up-do for her bridal session at White Rock Lake. By the end of the session she had taken the pins out of her hair and shook it out. She said she was more comfortable having at least part of her hair down. For the wedding day, she rocked a half-up half-down look.
Elena sported some silver tresses with a loose updo for her bridals. The day was hectic and rushed, and the skull pin she wore in her hair was actually upside down although you couldn't tell unless you were super close. For her wedding, the silver had faded out and her updo was more of a polished twist (and her skull pin was right side up.)
Whitney changed a lot between her bridal session and her wedding day. She actually had her dress modified and had straps sewn in. They matched the rest of her dress perfectly. She also changed up her hair and her bouquet!
Megan also had a very different look for her wedding day, largely in part to seasonal differences. Her bridals were shot about 4 months prior to her wedding so she had a more spring-y bouquet with lots of greenery. She went with a more autumn look for her September wedding adding some darker reds. She also switched up her hair from down and off to one side to an updo.
And there you have it. There are lots of reasons to do a bridal session and very few not to. The ultimate most important thing is for you to feel beautiful and confident on your wedding day and doing a bridal sessions helps achieve exactly this!