Technique advanced for better bootskin

Hello to all the forum, and staff of the situated one, I have a technical question. exists a way in order to improve the images before working to us in order to render them .bootskin? techniques that are not in a tutorial, make up of the trade, tutorial advance in order first experience to you, seeing on your situated one have not seen bootskin of quality advanced, trying with tutorial taken in net have not caught up optimal turn out to you, I address to expert you for councils and suggestions. Thanks