Firstly, where will the wedding reception be held? A hotel, a community hall? Will it be indoors or outdoors?
Secondly, does the bride have a colour scheme in mind? For mine, a hotel setting, I chose a cream and green theme because I didn't want the usual pastel shades.
I also knew that I did not want the hassle or thinking of such things from scratch so I chose a venue that offered decorations and themes for me to choose from. I simply picked which I thought looked nice :)