For those doing DIY Centerpieces

How are you guys handling the set-up process? Maybe it's a common sense question (I usually lack that ) but who will be setting these up at your RH? What time? You will be too busy being the beautiful bride that day...and you can't ask anyone in the bridal party...so

For those doing flower centerpieces, are you going to create them the night before? How are the flowers going to hold up?