CG Wizard is the easiest tool to center your plane, in a precise and accurate manner.
Only 6 steps

1. Mark the CG as per your plane's manual
2. Power on you CG Wizard, and launch the app
3. Put the CG Wizard sensor under the wheels of your plane
4. Measure the distance between main wheel sensors and front sensor
5. Point the buil in laser under the CG mark made on step 1, and measure the distance to main sensor
6. Add or remove weight on the plane until the balance point matches the distance taken on step 5