Here are some photos and I'll walk you through it:
These cards will fit in a standard A4 envelope (to fit a 5 1/2 x 4 1/4" card).
7 1/2 x 9 1/4" cardstock
Patterned Papers (I use three different ones)
Cut your cardstock to 9 1/4 x 7 1/2". Score at the below measurements:
Once you score on the 9 1/4" side, turn it to the left and score at 4 1/2".
Take that same piece and cut off the first 2".
With that strip, cut at 3 5/8" and then cut it in half so you have two 1 x 3 5/8" strips with the scoring already done (be sure to cut with the 1/2" score line at the other end). These are for the inside of the box card to add your embellishments.
On the main piece, cut down to the score line to create flaps for the box.
2 total at 5 1/4 x 2
6 total at 2 1/4 x 1 7/8
3 total at 2 3/4 x 1 7/8
Cut your patterned papers as above and adhere to the flaps. HINT: If you are using a directional piece of patterned paper, be sure to adhere it so when flaps are down, the images are the right side up. (See my inside flaps example)
Add strong adhesive to the side tab and adhere. HINT: Fold at the 2 1/8" and 6 3/8" score lines and fold these on top of each other for an even edge.
Apply adhesive to the inside strip (1 x 3 5/8) tabs and place them in the middle of the box. You should fold the card flat to make sure it will close.
I know it would be so much easier if I had done a video, but I hope this helped a little. Although there are many videos and instructions out there, I used the one at Splitcoaststampers.com. I love visiting this site for inspiration and ideas.
To add height to your embellishments and some fun (moving) elements, attach some embellishments to strips of transparency sheets or something similar.
Also remember, to check the placement of the embellishments every so often by folding the card. If items fall over the edge, they will not fit in the envelope.