Men asked something like that couple of month ago. I promised, forgot, remembered and finally did it (мужик сказал - мужик забыл). It's not a tutorial. Here on DA you may find thousands really talented and experienced men and women who not only draw fantastic pictures, but in addition do very nice tutorials about almost everything. It is not that case. But maybe you'll get to know something interesting from this 'bedsheet'.
The finished picture: [link]
By the way, I did step by step for this picture too: [link]
. You can find it here: [link]