Ladies! If you feel that you need Spanx or need to tell a friend that they need them;
1) make sure that the garment isn't too form fitting for spanx with a seam down the center, try and get seamless
2) if they are the long above the knee spanx take a step in the garment with your spanx on to see if they show through
3) in a special occasion garment it is always best to get the spanx that come up under your bust and no seam down the center
I recommend the Hide & Sleek Hi-Rise Body Smoother at Spanx.com
If you need the right bra;
try and find a bustier with no boning down the front
My personal favorite is the Felina Essentials Seamless Hidden Wire Bustier #7643 it is the model we sell at our store The Dress Doctor and I highly recommend.
If you are looking for coverage I recommend cups that can be sewn in or sticky chicken cutlets by NuBra. At The Dress Doctor we sell NuBras and also have sew-in cups that provide great coverage. The best model of sew-ins are called Three-Way petals at brazabra.com
A great place to purchase undergarments is Nordstrom. They let you return items which is great and also take your garment to their store to try on with the undergarment.
The best way to look great on your special day is to start from the inside and work your way out, no one wants to see a panty line!!