About the human hair bundles, I think most of the girls and ladies are familiar with them. With the human hair bundles being more and more popular, there comes out a question on how to install or wear them. There are a lot of of YouTube videos about hair sewn in. If it’s bundles on a weft (aka tracks), you would cornrow braid your hair, either straight back, or in a circular pattern,tucking the ends of the braids back in between the cornrows you just made and securing them with some thread. There are other patterns you can do if you want a part in your hair, or more volume at the crown, etc. You can also fortify your hair with synthetic braiding hair (cheap is fine) as you go along.
Then you would take hair thread and needle (found at nearly any beauty supply for $0.99 each) and sew the bundles in, either zigzagging across the head from the bottom up until the temple, then in a circular pattern, or going around in circles, following the circle braid pattern. There are other ways to do this, especially if you want a part. Hair thread is thicker than household thread and won’t break. Hair needles have a big hole for the thick thread and come in straight, curved, or “J” design. Curved is the most popular, because it can more easily get underneath a braid. “J” is a hybrid of straight and curved.
If you are still not familiar with doing it,I think it’s better to see a YouTube video of how the sewing is done to secure the hair as you go. Sew-Ins last anywhere between 1–3 months. You don’t want to go longer than that, because your new hair growth will have loosened the cornrowed braids too much, increasing the chance for hair breakage.