If you are the honoree of a shower, your attire should match the plan of the hostess, the invitation, or the theme. Ask the hostes what type of clothing she would like you to wear. This friend has gone to a lot of trouble on your behalf and hopefully has consulted you on the theme and tone of the shower. Everyone will know you are the bride, so leave the sparkling crystals and lacy dresses at home. This is a gathering of your friends and family, not another opportunity to wear a white dress and diamonds.
By using some common sense, you should be able to create an outfit which will keep you comfortable during a bridal shower. Taking a middle of the road approach and not trying to stand out is a reasonable solution if no guidance is available from the invitation or the hostess. And remember this feeling if you ever become the hostess and be sure to include a little wording on attire on your invitations.