I shared this project once before, maybe last year or so, but was thinking with so many people shopping for gift cards at this time of year, it might be a good project idea to share again. This example is birthday themed, but I think you could easily adapt it to a holiday theme.
To begin, I created my envelope with one strip of cardstock and one strip of pattern paper, both cut to 4" x 12".
Ink the edges on both sides of the cardstock and the printed side of the pattern paper.
Fold both in half so that they measure 4" x 6".
Adhere the pattern paper strip to the inside of the cardstock strip.
Fold one edge (cardstock and pattern paper) down 1 3/4" to create a flap on the front of the envelope.
Use adhesive or stitching along the open sides to create a pocket.
Punch a hole along the the seam at the top of the flap on each side of the pocket.
Wrap ribbon around the pocket and through the holes, tying the ribbon in a bow or knot on the front of the small flap.
Embellish the ribbon and flap as desired. (I embellieshed mine with a reprint of a vintage image, Prima flowers, sparkle brads, and walnut ink mini tags.)
For the insert in the pocket, I used a manilla shipping tag as my tag base. My tag was a little longer than my pocket so I shortened it to fit. If you don't have a tag you could easily create one freehand.
Use the tag as a template to cut a piece of pattern paper and a piece of clear vellum to fit.
Adhere the pattern paper to the tag and ink the edges.
Ink the edges of the vellum.
Adhere the vellum to the tag, attaching it only along the top.
Add a decorative brad or ribbon to the tag hole.
To add a gift card, add a small amount of adhesive from a tape runner on the back of the gift card. Adhere the gift card to the inside of the tag, under the vellum.
Using a small amount of adhesive make it easy to remove the card and leave the tag in good shape so that it can be hopefully repurposed.