Think pretty, think colourful, think gorgeous! You're there to celebrate your friend's happiest day! By default, you should be happy for him/her, and thus dress to this MOMENTOUS occasion appropriately.
Daytime wedding functions:
Choose simple and flattering silhouettes with minimal fuss.
Stay away from outfits that are too tight or revealing.
Some examples of great cuts that are appropriate for weddings:
Night wedding functions:
Night time events are usually glamourous and allows guests to don sequins on your outfit and bling on your phalanges!
As per day time wedding functions, stay away from anything that's too revealing or tight.
Think glam, think sexy, think classy and think flirty.
Maybe next post I'll share on what NOT to wear to a wedding.
Been through one of my own, and attended enough weddings to know what look absolutely RIDICULOUS at an event like that.