When making a
gift paper bag, the most important thing is to make sure the sides aren't visible. Then, you can flatten the corners and fold the top and bottom corners inwards. Once you've creased the edges, you can fold the top flap to the backside of the bag. You can also overlap the sides a little.
The next step is to wrap the gift. You'll need tissue paper or some other paper, which you can place on the gift or add to the bag itself. Tissue paper tends to wrinkle, so make sure you place it on a flat surface. Ideally, you'll want the tissue paper to cover the top half of the gift bag.
For your gift paper bag, you can choose from a wide variety of styles. Some are plain and unprinted, while others have a twisted paper strap or a fabric strap. There are also many sizes, from those for cosmetics to those for larger gifts. Whatever you choose, make sure it's a good basis weight.