The question about how to make a stylized Christmas tree can be answered in two ways here and the answers really depend on whether you are a computer savvy person looking to make some really good stylized drawing using adobe or any other drawing tools available or whether you are looking at the Christmas tree crafts for your kids.
As far making the tree then Christmas tree clip art along with the Christmas tree images will help you make one.
The only knowledge along with the software you will need is the Christmas tree images which are available dime a dozen on a lot of sites. Use these as example and then let your creative juices flow while using the either the Adobe software for making images or some other software which you are comfortable with.
If you are looking at making the real life stylized Christmas tree then you should try to make either are beaded Christmas tree or a miniature Christmas tree made out of the tree runners or the special lace and light combination.
The main structure that you need to make a tree is the wire around a conical surface long with a stand for the conical surface. The you can either make the tree using the safety pins attached to the wire or the nice runners attached and glued to the wire.
This wire can be then be wound around the conical surface. It will give the look of a tree which is homemade and simple. These trees are easy to make and if you want to make a tree which has the tree leaves as well then make sure to get artificial tree leaves or the tree tips which can be easily embedded into the Styrofoam surface and that way you can have natural stylized Christmas tree.