Just envision what you want it to look like and start cutting from the ground up. Then thin out any branches that are crossing or don't look right to you/too close together.
Then thin out the smaller branches/twigs so that it doesn't look like a bush on a stick. Your shrub is probably too large already to move to another spot.
Keep in mind that trees and shrubs grow out from the tips. The best way to describe this-if you hang a birdhouse in your bush 1' off the ground and come in 10 years, your bird house will still be 1 ft off the ground, it will not be up in the air some where. You should mulch your shrub heavily for winter. Do realize that if for some reason you have an unusually cold winter at some point, the crepe may die back to the ground or partially die back so that you may lose several years of shaping and have to start over. I can't grow crepes here, the winters are too cold, a few kinds I have had luck with coming back but they always grow back from the ground-a shrub. I cannot prune them into a tree form. Here is a link to pics that might help you decide what you want yours to look like. Basically you just have to find the main skeleton of your shrub and cut off everything that doesn't compliment that form.
https://www.google.com/search?...
