Our house has many big windows and I'm simply too cheap to buy that much window blinds :P
I came up with this inexpensive, easy and yet decorative window blind.
It takes about 30 minutes to make one.
Step 1: Materials
a big sheet of cardboard (the one i used was kind of sloppy and had a lot of holes in it - you may choose a nicer one)
a long straight piece of lumber or anything else - it has to be straight thats all, you'll only need it as help for cutting)
a knive or cutter
2 hairclips or clothespins
2 hooks or heavy stones
1 big needle for the twine (works without but it'll much easier with the needle)
Step 2: Measure your window
cut your cardboard the same size.
you'll need to know the depth as well.
Step 3: Impress the cardboard :)
let' say it is 5 inches deep, than you'll make your foldes about 2,5 inches.
mark lines with for example 2,5 inches distance,
take the straight piece of lumber (or whatever you use) and place it on the cardboard.
now takte the BACK of your knife or cutter and impress every second line,
DON'T CUT THROUGH the card board, the lines are only a help for folding the blind. you won't need much pressure.
See the pictures.
Step 4: Folding
press the fold hard with your hand.
see the pictures
Now turn the sheet around.
Step 5: Impress other side
now impress the remaining lines on the other side, and fold them too.
you'll end up with a zig-zag folded cardboard.