I don't really have a favorite place to download from but I do have my favorite hairstyles. I spent a lot of years looking for good hair and I only have a dozen or so that I truly love. I think Newsea has some of the cutest hairs.
Some look really cute till you put it on your sim and then it's like ugh..how'd they make their sim look so good in it? And long hair...it will stick out and look like it's hovering around your sim. I stick with shorter styles.
A couple of my favorites are Peppermint (newsea), Lavender (newsea), Foam Summer (newsea), Gravitation (newsea), Tsugumi (kijiko) Short? Medium? (unisex) (kijiko). Kijiko has quite a few cute short styles for both sexes.
R2M has some hairstyles that are resized to fit sims heads better - http://r2mcreations.blogspot.com/search/label/female%20hair#/page/1
https://chazybazzy.tumblr.com/tagged/hair%3A-female is a good place to get/find hairs cause there are a lot of them.
http://kijiko-catfood.com/category/the-sims3/ts3-malestyles/ts3-female-hair/
https://pocketfulofdownloads.tumblr.com/retextures - good to find by creator
Peppermint
https://i.imgur.com/W6Z4fv9.jpg
