Find an object you would like to turn to Ice. I'm using a skull in this example.



First select the object, I used the magic wand tool for this because the background is one color. now copy it, Ctrl + J ~ Now desaturate the layer; Shift + Ctrl + U ~



Now go to layers, layer blending mode arrow and select the exclusion mode.



Now copy the exclusion layer and set mode to screen 50%



Now make a layer of light blue and set it to overlay 50%



Now with a new layer, set mode to multiply and turn down opacity to 50%, brush in the shading into the eyes and nose for some depth. you can do a guassian blur to soften edges also.



Now hold down Ctrl click the top skull layer' then hold down Ctrl and Shift together + C ~ then Ctrl + V and that will merge all skull layers into one new layer. copy that layer Ctrl + J ~ and add a light blue layer on top of that layer and use a hard light layer mode about 50% over the layer you just created. you can adjust all these layers to whatever you like to get different lighting and color effects. all the layer below the merged layers can be shut off. you can use them later.



I did a soft inner glow of light blue for the edges and added a few details with a small brush here at this stage.



I added a gradient mask and set layer mode to screen to brighten edge.



Brushwork, cloning, clean up edges and do some blurs.



Before and After. ~ add as much detail as you want, textures, highlights, backround etc...