Proper flossing techniques
https://www.medbroadcast.com/channel/oral-care/oral-care/proper-flossing-techniques
White Tooth Dental Takeaways:
As mentioned in the article, if you have not been regularly flossing, you may (should!) notice your gums bleeding during flossing. Unless you are pulling so hard you are hurting yourself, the bleeding is an indication of active gum disease (gingivitis or periodontitis). With persistence and correct technique, the bleeding should resolve within a couple of weeks, but if it does not, you should see your dentist as soon as possible.
Though traditional string floss or tape is the best to use, if you are having challenges (because it is technique sensitive!), the floss picks or a water or air flosser are great alternatives.