The biggest mistake most brides make is shopping with too many people. Its normal to want to share the excitement with all your family, bridesmaids and friends. Caveat: Too many people equals too many opinions. And too many opinions leads to stress, arguments, squabbling, confusion and disappointment.
Shop with one or two people whose opinion you trust and who knows you and your taste: your mother, your sister, your best friend. The entire world DOES NOT have to be involved in your dress choice for your big day. Once you choose your dress, you can invite them to the bridal salon to view your choice.
When you shop with too many people, you get too many opinions. They are going to focus on what they like for themselves, not what is best choice for you. I've seen friendships break up over angry friends who INSIST their choice is better than the bride's opinion. I've seen jealous friends pick out the most unflattering dress for the bride and force her to try it on. And believe it or not, I once had the ex wife of the groom show up to give her opinion. It was really ugly.
Ultimately, you are the bride and your opinion is the only one that matters in your choice of the dress!