OP, not sure what your issue is as you did not specify.
If your trying to get your trim so you are more horizontal, there is no magic...just distribute the weight you are carrying to help you balance out. If you are feet high, either secure your BC higher on the tank moving more of the tank lower on your body, and/or attach some weight to your tank cam strap, or use ankle weights/heavier fins.
If you are head high, you can move your BC lower on the tank to move more mass towards your shoulders, or put an ankle weight around the neck of your tank.
If the majority of your weight is in the integrated pockets on the sides of the BC then split that weight up and put it where it is needed for you to be comfortably horizontal.
-Z
Edited: mixed up the recommendations for head high/feet high...should read correct now.