I love this name, I just can’t decide betwen Mylie Skye or Miley Skye. I love that Mylie Skye emphasizes the Y in both first and middle names, but I love the classic spelling of Miley too! Mylie feels spunky while Miley seems sweet.
I would go with Miley!! I think she flows much better with [name_u]Skye[/name_u] spelling wise, and is not as likely to be misspelled 
[name_f]Miley[/name_f] [name_u]Skye[/name_u] looks best to me
I prefer [name_f]Miley[/name_f] 
Definitely [name_f]Miley[/name_f]
I always opt for the most recognized spelling.
I actually think it would be the other way around. To me, “Mylie” looks more mellow and delicate because the “ie” spelling looks more nickname-y and immature, and the “Miley” spelling looks more spunky because of the “ey”. Also Miley is a lot like “smiley” and that word sounds kind of spunky in my opinion.