They are two ways - You take a seed, plant it into the soil, and water it. Or you make it my way. I have to admit, I stole couple of the buxus leaves from the front yard at the place where we had a rented apartment while staying in RI. Well, I was bored and the bush needed a trim anyways:)
This project was very simple. I know I always say it's simple but honestly, it is very easy. I wasn't at home in Slovakia, which means I was missing couple floral items that you can find at my house any time - like oasis... spongy foam for flower arranging. But, I found a piece of used oasis for dry flowers from previous renters in one of the kitchen cabinets. The trouble is that the dry one is harder to soak up with water. So, if you want to work on your own tree, just use the one I mentioned before (usually in dark green color but the company came up with new fun colors as well). I made a ball out of the foam using a knife. That will be the base for the buxus leaves. Look for straight piece of stick... that will be your tree trunk. The additional items you need is a flower pot, couple stones & see shells, and of course bunch of buxus leaves.
And because, I didn't have enough of the floral foam, not even the dry one, I had to improvise. I centered the stick in the pot and stuffed the pot with couple plastic bag. So much for recycling:) Than, I just covered the bags with stones and shells that I found at the beach. In your case, please use a piece of oasis that you cut in order to fit it in the pot and use as a base for the stick. Than, you just need to attach the formed oasis ball to the top of the stick (trunk) and you can start to arrange the leaves around the ball. You can also use any full bloom flowers (carnations look awesome). I hope I inspired you today a little bit. Have fun making trees!:)