When picking the flowers for a wedding, it sets the colour scheme for the entire day. Everything will be coordinated with these colours. It is very very rare that a person will pick two colours for flowers and than have completely different colour dresses and decorations. For example, having red and yellow roses when the bride's maids are dress in purples and the entire hall/reception area is decorated in purple and white does not match the ''theme'' and ''colour scheme'', picking purple lilies or tulips or roses even for that matter match the whole wedding and pull it all together. This of course does not matter for the bride because she is usually in white and every colour matches white, adding a ribbon or handle in the theme colour would match it all together, however matching a weddings colours should always be kept in mind when making wedding bouquets, boutonnieres, corsages and flower arrangements.
When getting married in countries that aren't familiar to at least the bride or groom, the flowers may present a problem. In some counties and/or religions certain flowers are considered bad luck and should be avoided. A little research would be needed to make sure that a bouquet doesn't conflict with such a belief in the country or religion the couple is being married in.
Ordering flowers can be a tricky thing especially if the couple is not local to the town, province/state, or country they decide to get married in. When picking flowers it is important to find a florist to get the flowers from and it is equally as important to make sure that they have the flowers needed to create the bouquets the couple wants. In some countries because of either growing conditions or the seasons, certain flowers may not be available at the time of a couples wedding so looking into such things before hand can save a lot of time and hassle.
Some couples think a great way to save money is to make their own wedding arrangements and bouquets. Unless the bride or groom is very skilled at handling flowers, arranging them and knows how to care for them, it is best left to a professional. In the end if a home made wedding bouquet doesn't turn out well, it could cost the couple twice as much as just letting a florist do the job in the first place.
**If throwing the bouquet is a tradition the bride and groom choose to follow, the bride may want to hold on to her bouquet and throw a fake or a stand in one. The best thing to do is to get a replica of the bride's original bouquet but scaled down so literally she isn't throwing money away. Also bouquet preservation may be something the bride would like to look into to keep her wedding bouquet as a souvenir of her big day, that is also something that should be discussed with the florist.**