Increase texture size with maintaining the quality (The Amazing Spider-Man)

In the beginning, we need to open in photoshop the texture that you want to enlarge. I took the example of Scarlet spider.
Screen 1
Then select the entire texture (Ctrl+A) and press copy (Ctrl+C).
Now click the top File > Create.... A dialog box appears with adjustable settings. The width and the height will automatically set the values of the copied image. To increase texture in two, for example, the times you need to multiply the parameters Width and Height two. That is, if the original texture was 1024*1024, then after the increase it will be 2048*2048.
Screen 2
After setting all parameters, click OK. There is a new image. While it is pure white. Click paste (Ctrl+V).
Screen 3
Now using free transformation (Ctrl+T) and stretch the image(you can even without holding down the Shift key).
Screenshot 4
You may be puzzling that after the texture stretching will look it is not acceptable and it would seem, what there nafig quality, but no. Need only to press Enter to apply the transformation effect is free, else photoshop will do it myself.
Screenshot 5
In principle, the texture is enlarged, and seems to be ready. However, we must not forget about the alpha channel, especially if you increase the texture of the terrain. But in the normal texture of the costumes has an alpha channel. And if not to take into account the relief, in most textures it is used to determine the transparency of the parts as textures and textures as a whole. In the textures of the costumes he's white. This means full opacity. So I prefer not to forget about this channel. So I recommend to create it. In the screenshot below, bottom right.
Screenshot 6
As soon as you create the alpha channel will be black and we need it white. Prozhimaet Ctrl+I to invert colors and voila - he's white. Now stored, replacing the original texture. If you have not saved, it means that you have not closed the original texture. Well, basically everything. There will be questions - write in comments.