Rule 34. Use A Telephoto Lens - Short telephoto lenses will prevent foreshortening (covered in rule # 23) which is where objects nearest the lens will appear larger than objects farther away.* Use of a short telephoto lens in group portraiture will make all the faces approximately the same size regardless of whether they are in the front row or the rear row. I used a short telephoto lens in virtually every one of the images in this tutorial.
Rule 35. Avoid Posing A Bride Kneeling on the Floor.* The wedding gown is designed to look correct and usually flows beautifully and therefore photographs best when the bride is standing.* A bride seated on a posing stool for a head and shoulders image or for a waist up or 3/4 length shot is of course perfectly acceptable.
As mentioned earlier, these "rules" are really guidelines. Once you know them you can judiciously break them.
I'm told rock musicians study the great composers of classical music to gain an understanding of the "rules" of composition in music so they can become great musicians in their genre.