YAKITORI

I can GOOGLE for yakitori and get a lot of articles for the version prepared with cubes of boneless and skinless chicken.  I also see frequent mention of yakitori made from chicken skin, but few details.  I'd like to hear from someone who has had or seen the chicken skin version made in a Japanese shop and / or made it on their own. 
 
Breast, back, or thigh & leg skin? 
 
Cut into squares or do you thread strips on to the skewers?
 
Also, if chicken heart or gizzard are used, do you cut into thin slices or cook the meat in chunks?
 
Also, I take it that if you used chicken "tails" or bachelor buttons y would simply thread the entire piece onto the skewer, right?
 
Any help is appreciated.