Go to Window > Brushes (F5) and select the ‘Frosted’ brush, then enter the following settings to change the brush’s behaviour: in the Brush Tip Shape menu, change the spacing to 10%. In the Shape Dynamics menu, set the size jitter to 100% and the minimum diameter to 20%. In the Scattering menu, change the scatter to 120% and the count to 5. In Other Dynamics, set the opacity jitter to 50% and the flow jitter to 20%.
Now create another layer above the bottle layer and start painting using the Frosted Brush. It’s important to paint only over the bottle area, so use the Pen tool (P) to create a path around the bottle, then right-click and choose Make a Selection. Convert this selection a layer mask (Layer > Layer Mask > Reveal Selection) to mask out everything but the bottle, then paint using this mask.
Now let’s add a thick ice layer is some areas of the bottle. To do that we’ll need to create another brush. Go to the Brush Engine (F5) and select a regular rounded brush of about 100 pixels. Then enter the following settings: in the Shape Dynamics menu, set the size jitter to 100% and the minimum diameter to 1%. In the Scattering menu, set the scatter to 0% and the count to 3. In the Texture menu, select the Noise pattern and change the scale to 20%. In the Other Dynamics menu, set opacity jitter to 50% and the flow jitter to 40%.