You will need four items:
1. A pine garland strand, or wreath, that is plain
2. Craft wire
4. Wire Cutters, or a good pair of scissors
You take the plain garland strand, and buy a bunch of stems from Michaels. They always have them in the front of the store, it's a bunch of cute little Christmas-y type decorations and you always wonder to yourself what purpose they serve. Usually these little stems are about .50 cents to $1 apiece, really cheap.
Then, you take the stems and attach them to the garland using the craft wire, which is green and matches the garland so it is discreet. Wrap the craft wire around the center of the stem in a hidden place, wrapping it a few times around the center of the garland so it stays in place. Voila!! You have your very own garland, made very cheaply, and to your own personal style and house decorations.