How to Decorate a Wedding Archway. Part of the series: Wedding Decorations. Decorating a wedding archway involves draping sheer fabric, attaching flowers with wire and stringing lights around the supports. Personalize an archway to match the wedding colors with advice from a certified wedding planner in this free video on wedding day decorations. Read more: http://www.ehow.com/video_5538947_decorate-wedding-archway.html