So I've been trying to make a tissue case for the past couple of months. I was going off of a tutorial online but it was for the Puff's traveling tissues (haha, like a circus act) and all that Wal Mart (the only store in an hour's drive) has in stock are the Kleenex ones.
I tried figuring out what size to make my pattern. And apparently high school math was too long ago that I ended up with Mini Me as a Tissue Case (I'm thinking it might fit a birth control pill pack but I'm not sure since I'm not on the pill).

With some more adjustments, I ended up with this:

It's still too short (length wise) but it's an improvement. I was able to trim a couple centimeters from the tissues and they fit.
And finally, after scouring the internet for actual dimensions of my pack of tissues, I used 7" by 7" dimensions and it finally worked:

I'm still going to work on some other dimensions. I've seen some people have holders that have the two flaps of fabric overlap and I'd like to get to that point.
So for everyone who has tried making tissue cases and figuring out their own dimensions and keep screwing up, 7" by 7" works for the Kleenex 2ply, 15 sheets, 21 by 21 cm

Made some new ones on Sunday while watching Army Wives:

-------------TUTORIAL--------------So I made another one tonight and took pictures. This original tutorial is from someone else, nicely titled the
The Lazy Ass Bastard Method. Mine must be v.2.0 because I throw caution to the wind and don't do some things. Here goes.
1. You will need a sewing machine or hand sewing skills and patience. And normal notions. This tutorial is for the following type of tissues:

You will need to pick out two types of fabric, one for the outside and one for the lining. I normally just use two normal cottony-types but I have done the lining with a linen-y fabric before too (it was duck cloth actually). If you want to interface the fabrics, go for it. I do not. I chose black for the interior and a cherry blossom print for the exterior. Cut a 7 x 7 inch square out of each fabric, like so:

2. Now you want to pin the hell of these suckers, right sides together:

(If you'll notice, at the top, there is a gap between the only two pins. This is where you'll leave a hole to turn the project out.)
3. Now we get to sew:

(You may have asked yourself, what if I cannot cut straight? Take a gander at the photo above and have no fear, I can't either. I also sew with pretty big seam allowances, so yay for mediocre sewers!)
4. a) When you are done sewing, cut the threads. Don't forget to backstitch at both ends. It should look like this (aided by photoshopped lines to show where the stitching should be):

(I told you I was lazy, I didn't even iron! Gasp! Ha, and this is even worse: I didn't pre-wash this either. I never do.)
b) Using pinking shears, or scissors, cut the three sides that were fully sewn. For the side that has your turning-inside-out-hole, do not trim it, like so:

(I can't sew straight either. Whatev. The beauty of this project is that you can't see any of the sewing when you're done.)
5. Turn that sucker out. For the first time in this project, I did not take a photo at every second. Take your square (with the raw edges on the hole end folded in so it looks like the rest of the project) and fold two opposite edges in so they meet in the middle. Actually, make sure the two ends you're folding in do not have the hole. You should also have the exterior fabric showing, for me, its black. Pin the sides, like so:

6. Time to sew again! And I didn't take a photo. But, you're going to sew as close to the edge as possible (so 1/4" for me, ha) for both ends. It's a good idea to backstitch over the middle section to reinforce it. I really don't know if that reinforces it or not, it just sounds like it does. When you're done, pull the project out. Here's a picture of what I faced:

(Multiple threads coming from below. I don't know what causes this but I get it ALL the time. Does anyone else know?)
7. Turn your project inside out!

8. Stuff some tissues in there!

I usually take the tissues out of their plastic stuff and put them in there myself. I bet it's more sanitary to leave them in the plastic. Especially since you can pull this tab thingy off the back and pull tissues out one at a time, even from within the fabric case.
There you have it. The Lazy Ass Bastard Method v.2.0.