Make the quotes meaningful
Think about the songs, the films, the books that mean something to you both. Do any of these lend themselves to a great quote? Guaranteed, the bride will love you more for it.
Don’t overload your speech with quotes
Two maximum as a general rule. One at the top and one towards the end.
Quote recognisable names (or at least provide some context)
It’s always good to quote people that you’ve actually have heard of (or at least respect after you’ve looked them up on Wikipedia). You’ll find there’s loads of great quotes by people you’ve never heard of, but do you really want to qualify them by saying they were written by a ‘relationship consultant’?
Don’t just use quotes for the sentimental bit
Quotes can also add humour where it’s needed.
Add a back ref
Put the quote into a personal context, or make it humorous with a suitable ‘ad lib’.