Now let me have a short introduction on myself about my change between "now"and"past".
First,on my appearance,I used to be a dark skin girl who had very short hair,it made me looks like a boy,but now I become fair and have a waist-deep hair.Then,when talking about my character and habbits,I used to be a very shy and negetive person and like doing everything alone,but now I have changed,I become positive,I like going out with my friends and enjoy the nature,I think this is the most worthful change.
Well,that's my "used"and"but",welcome to be my friends.
你也没有描述你的特征,我就按照自己的写了,你可以适当改成你自己的变化,大致套路就是这样的.