Select a vase for the arrangement. Choose a traditional glass or china vase or opt for something unusual such as a crock or even a mason jar. Select a vase that is about one-half the height of the carnations.
Open the envelope of flower food and pour it into the bottom of the vase. Fill the vase almost to the top with cool water and mix the water and flower food with a long spoon.
Fill the bucket with the cool water. You will use this bucket to hold the cut carnations temporarily while you construct the flower arrangement.
Remove all of the leaves from the bottom half of the carnation stems. This will prevent the leaves from fouling the water in the vase. Cut the carnation stems at a 45-degree angle just above a leaf node. This will enable the carnations to draw water effectively up the stems. Place the cut carnations into the bucket of water immediately after cutting them.
Prepare the filler flowers and the greens by removing all of the leaves from the bottom half of these stems also.
Add the greens to the vase by creating a layer around the opening of the vase. Add three or four stems of greens to the vase so that the greens extend out in all directions from the vase.
Place the tallest carnation into the vase in the center of the vase. Add two additional slightly shorter carnations to the left and right of the center carnation. Add five to seven slightly shorter additional carnations around the outer edges of the vase.
Add the filler flowers in the gaps between the carnations to finish the arrangement.
Check the floral arrangement daily and add water each day to keep the vase full. Every third day, remove the flowers from the vase and pour out the water. Add more flower food and fresh water, mixing as you did in step two. Cut the carnations again in the same way you did in step four and then construct the floral arrangement again.