I would say the first thing to do would be to wire the trunk and put some movement in the trunk. The bends should be greater than you want in the final design. As the tree grows and the trunk thickens the curves will reduce.
Also make sure the bends are in all directions. To the left, right, front and back. Make sure the top of the tree points towards your chosen front. Also if you are going to keep my branches place the curve so they are on the outside of the curves.