Begin with one sheet of 8-1/2 by 11 paper.  I used standard college ruled notebook paper, but I'm sure just about any kind will do.

Fold over the top left corner, and make the top side flush with the right side (as seen in the picture). Crease your fold.

(No, I'm not left handed.  I needed my right hand to work the camera.)

Fold the now narrow and pointy top down so it meets the bottom right corner of the paper.

Fold the left side of the paper over so you make a square.  It's good to leave a little space between this and the fold in step 3 to make the next step easier.

Fold the bottom half of your square up so you make a triangle, like so.

Flip your triangle over so the closed side (the side with the creases) is on your right.

(This step isn't really necessary, but that's how I learned to do it and I confuse easily, so I haven't changed it.  Just humor me.)

Fold the closed side of your triangle down like the picture shows.  The angle pointed out is very important, because it determines how your claw will fit your finger.  I find about 115-degrees fits me pretty well, but you can play around with it to see what size works for you.

(You don't need a protractor.  Eye-ball it.)

Now, start wrapping the excess paper on the left side of the triangle around the piece you just folded.

When you run out of paper to wrap, tuck the bit that's left into the nearest pocket.

Congratulations!  You've finished your claw!  To put it on, stick your finger into where the arrow is pointing.

If  you can't get your finger in, or you find that the claw is cutting off the circulation to your finger tip, unroll it and try messing with that angle some more.

Now you can decorate them anyway you want, to either compliment your Halloween costume, or add to the affect you'll have when you wave at people.  Suggestions: cover them with silver duct tape for instant Wolverine claws, or get a red marker and add some fake blood.

>:D *evil grin*  hehehe...