You want your fresh flowers to be completely bare from leaves.  You will need to do this to every stem of flowers that you purchased for the corsages, boutonnieres, wedding bouquets, reception flowers, etc.

You will then need to cut the stems of each flower that you purchased for your wedding flowers.  Cut the flowers at an angle with a knife.  The reason you cut them at an angle is because it allows more area on the stem to get water.  Please cut the stem at least 1 inch from the bottom - do not use scissors or the wire cutters to cut the stems, as it will break some of the little veins that it uses to suck up water.

Now insert you flowers into the water and let them sit for at least a day sucking up water. 

For those people that want to make their white rose blue, or another color that flowers do not grow - this is where you add food coloring to the water.  Flowers will suck up the dye and change color.  Please keep in mind if you are trying to change the color of your flowers, you will need to change the water frequently (at least once a day) as well as making a new cut in the stem, again at least 1 inch.  If you are planning on changing the color - make sure that you get a sample flower ahead of time to see how long it takes to make the flower the color you want it.  Sometimes it can take up to one week to make the flower change color.  You will need a lot of dye in the water - way more that you would use to make icing for a cake.  You should practice this ahead of time.