This card technique may look intimidating but it really isn't. Not done this way. The one I found intimidating was the one where you had to trim up the mechanism after you constructed it. These instructions have you making the mechanism different and when you fold it on the score lines, it's done!
There are some tips I have learned along the way and I'll share them with you here. When you go to tape the mechanism piece in place, put the tape on the entire triangle using strong tape. Then set it in place on the inside of the card. Make sure you get the tip of that triangle right on the fold like of the card base. The sticky side is facing you so you can move that piece around until it's centered. It doesn't have to be perfectly centered but close. Then close the top of the card. Next, open it up and tape the entire triangle on the other side and close the card. If you have the tape facing you it makes it easier to move the piece around. All of the other instructions I saw had you just taping it in place like you would a layer. It didn't matter if you had the tape facing you, so that is how I do it. And when you tape the valley, mountain, valley folded piece in place, you want to fold it in half. That way you can see center. Line it up with the edges of the mechanism piece and press in lace. Open the piece up and adhere it to the other side. Doing it this way will save you some frustration in getting that folded focal piece to be centered. When you are done make that center fold a mountain fold again. Close the card to test the mechanism. It should work perfectly!!!
You can see another card I made using this fun technique here and the link to the instructions can be found there as well.
When making these, keep in mind that you don't want a lot of bulk on the inside valley, mountain, valley folded piece. It ha to close up and it's bulky enough.
You can add decorative paper to the inside before you add the mechanism piece or you can add it later. With this card, I cut two piece to fit the space below the mechanism piece. Follow the video and use my tips and you will be whipping up these in no time!!