Add another layer and mask it as in step 8, to make sure that you will paint only over the bottle area. Select your new brush in white and start painting some areas that will be frozen. Change the sizes of the brush using the keyboard shortcuts [ and ] to create a varied, more realistic effect – paint with a big brush first and then a very small one. Use a very light grey to create details, such as the shadows right below the bottle cap and the bottom of the neck of the bottle. These little details with the grey brush will add a great depth to the ice effect.
Add another layer and, using the same brush at a small diameter, carefully paint a border around the bottle: this will create the rough frozen edge. Also paint over the edges of the ice in the middle of the bottle to create a subtle 3D effect.
Add another layer, this time right above the frosted-effect layer and, using a normal rounded brush, paint some circles that will become water dots. Vary the size, but make most of them small, with only a couple of larger ones. Then select Layer > Layer Styles > Drop Shadow, setting this to 40% opacity, with the blend mode set to Color Burn, the distance set to 1 pixel and the size set to 2 pixels. Next, select the Inner Shadow menu and use 75% opacity, set the angle to 90º, the distance to 0 pixels and the size to 1 pixel. In the Bevel and Emboss menu, enter the following settings: depth – 730%; size – 4 pixels; soften – 3 pixels; angle – 151º; altitude – 37º; shadow mode – Color Burn with 30% opacity, in a dark red.