1. Launch "Icing On The Cake Online" on your mobile device.

2. Wait for the cake model to appear on the screen. This is the base cake that needs decorating.

3. Observe the reference cake shown in the top corner or before the level starts. This is your guide for decoration.

4. Tap and hold your finger on the screen to start spreading icing on the cake.

5. Move your finger around to apply icing to different areas of the cake.

6. Match the colors and layers of icing as closely as possible to the reference cake.

7. Use the rotating platform to view and decorate all sides of the cake.

8. Switch between different icing colors by tapping the color options available.

9. Use the tools provided, like smoothers and spatulas, to even out the icing and fix mistakes.

10. When you think your cake is complete, tap the "Done" button to finish.

11. The game will compare your decorated cake to the reference and give you a score based on accuracy.

12. Try to get as close to 100% match as possible to unlock new levels and challenges.

13. Have fun experimenting with different icing techniques and enjoy the relaxing gameplay.