Answer: Probably the best thing you can do to improve the long lasting quality of your cut branches is to display them in as cool a location as possible, and certainly out of direct sun. In addition, right after cutting them from the tree, lightly smash the cut ends of the branches and plunge them entirely under water overnight. This will work to hydrate them as best as possible prior to arranging them.
Part of the charm (and extravagance) of using fresh cut live evergreens is their short shelf life. Although some of the broadleafed evergreens can be treated with glycerine and last indefinitely, this is not the case in my experience with the needled evergreens.
You might find that the web page from Clemson
"Holiday Decorating with Fresh Greenery" includes some additional pointers on using pine helpful.
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