My parents tried to treat my older sister and I equally most of the time but then they fell into favourites and labels. My sister was the 'smart one', I was the 'pretty one' even if they didn't say it in so many words. Funny thing is that we became each others cheer squad- I would try and boost my sister up for things my parents wouldn't notice and visa-versa. Now she's my best friend and I love her SO much. So in short, I don't know what the secret is because even with some crummy parenting we turned out well