It's very long winded, and image heavy, but here's the tutorial for my
nintendo bag.
Here are all the pieces needed for a basic bag:

If you want to make a Nintendo controller bag, use this template:
jpeg or
vector The grey border of the controller should be one piece and be the same width as the flap (including seam allowance) so it can be sewn to the very edge.

Start by cutting out all the pieces
For the A, B, START, SELECT, and D-Pad, sew the button to the button back first.
Like so:
*I used plain old scotch tape instead of pins or glue to hold everything in place while sewing.Sew the grey border to the flap, then on sew all the buttons.
PIPING:To make the piping for the flap (if you’re crazy and made it like I did the first time) take the piece of the fabric you want to use that has been cut 2 x 34” and fold it over (lengthwise) the 34” piece of cording. Pin it so it doesn’t unfold. (*gasp*, vinyl and pins! But you won’t see the holes anyways)Take your piece of piping and tape it on the good side of the bottom part of your flap. The fold should be facing in towards the center.

Using BIG stitches (I had mine 4.5mm) baste (sew big stitches) the piping onto the fabric.
Now put the controller flap half on top of the flap half with the piping, good sides facing in.
Changing the stitch size to 3.5mm and sew along the stitch line you made when you basted on the piping. When it’s done, it should look like this:

You’ll notice that I did a bad job sticking to the original line I had drawn on, but that’s all right, no one will see it.
Flip the flap right side out and sew on the fasteners by hand. That is of course unless you have an uber sewing machine that can sew through many layers of vinyl AND that stuff the nylon straps that attach the fasteners. My Pfaff, as wonderful as it is, couldn’t quite handle it.

Congratulations! You are now done the entire flap! Sit and amaze at its wonder.
The rest of the bag:Start by making more piping! w00t. You need to make two more things of it, this time 38” long, but other than that, exactly the same as last time.
Baste the piping to the 4.5 x 37” piece of fabric (the one for the outside fabric, not the lining one), the fold of the piping facing in, one on each side.

If you want any pockets on the outside of your bag, now is the time to sew them on. I made a cellphone holder on mine, as well as one on the front under the flap.

Pin the bag together, good side in. Pin the other part of the fasteners in between the bottom and front (I didn’t do this on the original bag, but it looks much better this way)

Sew along the stitches you made when you basted on the piping.
Turn right side out! It should look something like this:

Next you need to make the lining. To do this you sew the three lining pieces together the same way you did the outside of the bag, but without the piping, so it’s much easier. If you want pockets in the lining, add those before sewing the pieces together.
To make the strap you take the long piece of 4” wide fabric and fold it over like this:

If you’re using vinyl and can’t pin it, use paper clips and tape (they work very well)
Once the strap is done you’re ready to sew it together.
Pin (doesn’t matter if you’re using vinyl or not) the strap to the outside of the bag but facing down (so the strap goes underneath the bag) leave about 4 inches extra on either side.

Now put the bag (with strap attached) in the lining. The lining should have its good side facing in. If your lining has a specific back, make sure that it’s pinned to the back of the bag.
Sew around the sides and the front but NOT THE BACK!
Flip right side out through the hole left by not sewing the back.
Feel where the strap is in the bag and sew and square with an x through it over the strap.

Put the flap in the hole and sew along the bottom of the flap (I do this twice making the seams about a centimeter apart)
Now sew along the top edge of the bag on the sides without the flap and VOILA!

Yes, I know it's not the nintendo one, but I didn't think to take photos while making that one...
EDIT: I finally fixed the links, I'm sorry that the images were unavailable for so long
