Here are some helpful tips:
1-Break off about 18 inches of floss and wind most of it around one of your middle fingers. Wind the remaining floss around the same finger of the opposite hand. This finger will take up the floss as it becomes dirty.
2-Hold the floss tightly between your thumbs and forefingers. Guide the floss between your teeth using a gentle rubbing motion. To avoid injuring your gums, never snap the floss into the gums.
3-When the floss reaches the gumline, curve it into a C shape against one tooth. Gently slide it into the space between the gum and the tooth.
4-Hold the floss tightly against the tooth. Gently rub the side of the tooth, moving the floss away from the gum with up and down motions.
5-Repeat this method on the rest of your teeth. Don't forget the back side of your last tooth.