It depends on your hair type but 6" is best for starting natural permanent dreadlocks. At least 4" for braid-in synthetic.

You just need to thoroughly shampoo your hair with a clarifying shampoo 2 - 3 days before your service. And remember, no conditioner ;-)

They are a fun confidence booster! They can simplify your hair routine while "spicing up" your look! They allow you to try without fully committing ;-).

This will depend on what service you are getting and the length and density of your hair.